Physical regeneration. Regenerative processes in the body

Regeneration (from the Latin regeneratio - rebirth) is a process of renewal of all functioning structures of the body (biomolecules, cellular organelles, cells, tissues, organs and the whole organism) and is a manifestation of the most important attribute of life - self-renewal. Thus, physiological regeneration at the cellular and tissue level is the renewal of the epidermis, hair, nails, cornea, epithelium of the intestinal mucosa, cells peripheral blood etc. According to the isotope method, the composition of atoms human body within a year it is updated by 98%. In this case, the cells of the stomach mucosa are renewed in 5 days, fat cells - in 3 weeks, skin cells - in 5 weeks, skeletal cells - in 3 months.

Regeneration in in a broad sense words are the normal renewal of organs and tissues, and the restoration of what was lost, and the elimination of damage, and, finally, reconstruction (reconstruction of the organ).

The body has two main strategies for tissue replacement and self-renewal (regeneration). The first way is that differentiated cells are replaced as a result of their formation of new ones from regional stem cells. An example of this category is hematopoietic stem cells. The second way is that tissue regeneration occurs due to differentiated cells, but retaining the ability to divide: for example, hepatocytes, skeletal muscle and endothelial cells.

Regeneration phases: proliferation (mitosis, increase in the number of undifferentiated cells), differentiation (structural and functional specialization of cells) and morphogenesis.

Types and forms of regeneration

1. Cellular regeneration is cell renewal as a result of mitosis of undifferentiated or poorly differentiated cells.

For the normal course of regeneration processes, a decisive role is played not only by stem cells, but also by other cellular sources, the specific activation of which is carried out by biologically active substances (hormones, prostaglandins, poetins, specific growth factors):
- activation of reserve cells that have stopped at early stage their differentiation and not participating in the development process until they receive a stimulus for regeneration

Temporary dedifferentiation of cells in response to a regenerative stimulus, when differentiated cells lose signs of specialization and then differentiate again into the same cell type

Metaplasia is a transformation into cells of a different type: for example, a chondrocyte is transformed into a myocyte or vice versa (an organ preparation as an adequate determinant stimulus for physiological cell metaplasia).

2. Intracellular regeneration- renewal of membranes, preserved organelles or an increase in their number (hyperplasia) and size (hypertrophy).

3. Biochemical regeneration- updating the biomolecular composition of the cell, its organelles, nucleus, cytoplasm (for example, peptides, growth factors, collagen, hormones, etc.). The intracellular form of regeneration is universal, since it is characteristic of all organs and tissues.

Reparative regeneration(from Latin reparatio - restoration) occurs after damage to a tissue or organ (for example, mechanical trauma, surgery, the action of poisons, burns, frostbite, radiation exposure, etc.). Reparative regeneration is based on the same mechanisms that are characteristic of physiological regeneration.

Very high ability to repair internal organs: liver, ovary, intestinal mucosa, etc. An example is the liver, in which the source of regeneration is practically inexhaustible, evidence of which is widely known experimental data obtained on animals: with 12-fold removal of a third of the liver over the course of a year in rats by the end years, under the influence of organotherapy drugs, the liver restored its normal size.

Reparative regeneration of tissues such as muscle and skeletal has certain characteristics. For muscle repair, it is important to preserve small stumps at both ends, and for bone regeneration, periosteum is necessary. Reparation inducers are biologically active substances released when tissue is damaged. In addition, individual fragments of the same damaged tissue can be inductors: complete replacement of the skull bone defect can be achieved after the introduction of bone filings into it.

Reparative regeneration can occur in two forms.

1. Complete regeneration - the area of ​​necrosis is filled with tissue identical to the dead one, and the site of damage disappears completely. This form is typical for tissues in which regeneration occurs predominantly in cellular form. Complete regeneration includes the restoration of intracellular structures during cell degeneration (for example, fatty degeneration hepatocytes in people who abuse alcohol).

2. Incomplete regeneration – the area of ​​necrosis is replaced by connective tissue, and normalization of organ function occurs due to hyperplasia of the remaining surrounding cells (myocardial infarction). This method occurs in organs with predominantly intracellular regeneration.

Prospects for scientific research on regeneration. Currently, organopreparations are being actively studied - extracts of the contents of a living cell with all its important cellular macromolecules (proteins, bioregulatory substances, growth and differentiation factors). Each tissue has a certain biochemical specificity of its cellular contents. Thanks to this, it is produced a large number of organic preparations targeted at specific tissues and organs.

In general, the direct influence of organopreparations, as standards of cell biochemistry, consists primarily in eliminating the cellular imbalance of bioregulators of regeneration processes, maintaining the balance of optimal concentrations of biomolecules and preserving chemical homeostasis, which is disturbed not only under any pathology, but also during functional changes. This leads to restoration of mitotic activity, cell differentiation and regenerative potential of the tissue. Organic preparations provide the quality of the most important characteristic of the process of physiological regeneration - they contribute to the appearance in the process of division and differentiation of healthy and functionally active cells that are resistant to environmental toxins, metabolites and other influences. Such cells form a specific microenvironment, characteristic of a given type of healthy tissue, which has an inhibitory effect on existing “plus tissues” and prevents the appearance of malignant cells.

So, the influence of organopreparations on the processes of physiological regeneration is that, on the one hand, they stimulate immature developing cells of homologous tissue (regional stem cells, etc.) to normal development into mature forms, i.e. stimulate the mitotic activity of normal tissues and cell differentiation, and on the other hand, normalize cellular metabolism in homologous tissues. As a result, physiological regeneration occurs in homologous tissue with the formation of normal cell populations with optimal metabolism, and this entire process is physiological in nature. Thanks to this, when an organ is damaged (for example, skin or gastric mucosa), organ preparations provide ideal reparation - healing without a scar.

It must be emphasized that the restoration of mitotic activity and cell differentiation under the influence of organ preparations is key in correcting defects and anomalies in the development of organs in children.
In conditions of pathology or accelerated aging, physiological regeneration processes also take place, but they do not have the same quality - young cells appear that are not resistant to circulating toxins, do not perform their functions sufficiently, and are not able to resist pathogens, which creates conditions for the preservation pathological process in a tissue or organ, for the development of premature aging. Hence, the expediency of using organopreparations as means that can most effectively restore the regenerative potential and biochemical homeostasis of tissue, organ and the whole organism and thus prevent the aging process is clear and obvious. And this is nothing more than revitalization.

Regeneration can be physiological reparative And pathological. The regeneration process is very close, in fact identical hyperplastic process(reproduction of cells and intracellular structures). They differ in that hyperplasia (hypertrophy) usually occurs due to the need to enhance function, and regeneration - with the “goal” of normalizing function when an organ is damaged and part of its mass is lost. Previously, it was believed that regeneration was limited only to the organ and tissue levels. It has now become obvious that physiological and reparative regeneration is a universal phenomenon, characteristic not only of the tissue and cellular levels, but also of the intracellular level, including the molecular one (regeneration of damaged DNA structure). Thus, after a pathogenic effect and damage to DNA, it is “healed”, carried out by the sequential work of repair enzymes. They “recognize” the damaged area, expand it, i.e. as if they clean the site of damage, and then “build up” the resulting gap along the complementary undamaged DNA strand and “stitch” the built-in nucleotides. The most remarkable thing about the DNA repair process is that it, as it were, repeats in miniature those main links of the regenerative process that we are accustomed to observing when it unfolds at the tissue level - damage, enzymatic breakdown of dead tissue and cleansing of the damaged area within healthy tissues, filling the resulting defect with newly formed tissue of the same type (complete regeneration) or connective tissue (incomplete regeneration). This indicates that with all the seemingly infinite variety of processes unfolding in the body, each of them, in principle, proceeds according to some universal standard scheme common to all levels of organization.

Regeneration, occurring at the molecular and ultrastructural levels, is limited to cells, and therefore it is called intracellular. Structural support for the body’s adaptation to everyday influences environment provided by corresponding intensity fluctuations physiological regeneration , which in case of illness sharply intensifies and takes on the character reparative. Both physiological and reparative regeneration in some organs is ensured by all its forms - cellular (mitosis, amitosis) and intracellular. In organs and systems such as the central nervous system and heart (myocardium), where cell reproduction is absent, the structural basis for the normalization of their function is exclusively intracellular regeneration. Thus, the latter is a universal form of regeneration, characteristic of all organs without exception.

Reparative regeneration It can be complete, incomplete and intracellular.

Cellular form regeneration is inherent in the following organs and tissues (bone, hematopoietic, loose connective tissue, endothelium, mesothelium, mucous membranes of the gastrointestinal tract, genitourinary system, respiratory organs, skin, lymphoid tissue),

To organs and tissues where it predominates intracellular form of regeneration, include the myocardium and nerve cells.

In some organs, cellular and intracellular forms of regeneration are observed - liver, kidneys, lungs, smooth muscles, endocrine glands, pancreas, autonomic nervous system.

The morphogenesis of the reparative process consists of two phases - proliferation and differentiation. The first phase involves the reproduction of young undifferentiated cells (cambial, stem or progenitor cells). By multiplying and then differentiating, they make up for the loss of highly differentiated cells. There is another point of view about the sources of regeneration. It is assumed that the source of regeneration can be highly differentiated cells of an organ, which, under conditions of a pathological process, can be rebuilt, lose some of their specific organelles and at the same time acquire the ability for mitotic division with subsequent proliferation and differentiation. The outcomes of the regeneration process may vary. In some cases, reparative regeneration ends with the formation of a part identical to the dead one - then they speak of complete regeneration or restitution. In others, incomplete regeneration (substitution) occurs. In the area of ​​damage, tissue that is not specific to this organ is formed, but connective tissue, which is subsequently subject to scarring. In this case, the remaining structures compensatory increase in their mass, i.e. hypertrophy. Regenerative hypertrophy occurs, which is an expression of the essence of incomplete regeneration. Regenerative hypertrophy can be carried out in two ways - hyperplasia of cells (liver, kidneys, pancreas, lungs, spleen, etc.) and ultrastructures (hypertrophy of cells - myocardium and neurons of the brain). Mainly those tissues that are characterized by cellular regeneration are completely regenerated; striated muscles, myocardium, and large vessels are incompletely regenerated. Regeneration.hypertrophy is observed in the liver, lungs, kidneys, endocrine glands, VNS.

Pathological regeneration– a distortion of the regeneration process towards hyporegeneration or hyperregeneration, in fact this is an incorrectly proceeding reparative regeneration. Examples of such regeneration and their reasons are:

1. The tissues have not lost their regenerative ability, but due to physical and biochemical conditions, regeneration takes on an excessive nature, resulting in tumor-like growths and leading to dysfunction (intensive growth of granulation tissue in wounds /excessive granulations/, keloid scars after burns, amputation neuromas).

2. Loss of habitual, adequate rates of regeneration by tissues (for example, in case of exhaustion, vitamin deficiencies, diabetes) - long-term non-healing wounds, false joints, epithelial metaplasia - in the focus of chronic inflammation).

3. Regeneration is of a qualitatively new nature in relation to the emerging tissues, which is associated with the functional inferiority of the regenerate (for example, the formation of false lobules in cirrhosis of the liver), and sometimes its transition into a new qualitative process - a tumor.

Regeneration carried out under the influence of various regulatory mechanisms:

1) humoral (hormones, poetic factors, growth factor, kelons)

2) immunological (the fact of transfer of “regenerative information” by lymphocytes has been established, stimulating the proliferative activity of cells of various internal organs

3) nervous and

4) functional (dosed functional load).

The effectiveness of regeneration processes is largely determined by the conditions in which it occurs. The general condition of the body is of great importance in this regard. Exhaustion, hypovitaminosis, impaired innervation, etc. have significant influence on the course of reparative regeneration, slowing it down and transforming it into pathological. The degree of functional load has a significant influence, the correct dosage of which promotes regeneration (restoration bone tissue for fractures). The rate of reparative regeneration is to a certain extent determined by age, constitution, metabolism, and nutrition. They also matter local factors– state of innervation, blood and lymph circulation, nature of the pathological process, proliferative activity of cells.

Wound healing occurs according to the laws of reparative regeneration. Depending on the depth of the defect, the type of tissue and treatment methods, 4 types of wound healing are distinguished.

1. Direct closure of epithelial defect, in which there is a creep of epithelial cells onto the surface of the defect from the area of ​​​​the edges of the damage.

2. Healing under the scab occurs in small defects, on the surface of which a crust (scab) forms, under which epithelial cells grow within 3-5 days, after which the crust disappears.

3. Primary tension.

4. Secondary tension.

Healing by primary intention occurs in the area of ​​treated and sutured skin wounds or minor defects of organs and tissues, in which, due to mild tissue trauma and low microbial invasion, dystrophic and necrobotic changes in cells and fibers are minimal even at the ultrastructural level. The primary reaction of mast cells and microcirculation vessels is relatively weak, therefore exudation is moderate and serous in nature, the neutrophil and macrophage stages of the inflammatory cellular reaction are weakened due to the low concentration of mediators that determine the chemotaxis of these cells. This leads to quick cleansing wounds and the transition to the proliferative phase - the appearance of fibroblasts, new formation of capillaries, then argyrophilic and collagen fibers. Granulation tissue, which primary intention weakly expressed, ripens quickly (10-15 days). The surface of the defect is epithelialized and a delicate scar is formed at the site of the wound.

Healing by secondary intention occurs with large and deep open defects, with active microbial invasion through suppuration. At the border with dead tissue, demarcation purulent inflammation develops. Within 5-6 days, necrotic masses are rejected (secondary wound cleansing) and granulation tissue begins to form at the edges of the wound. Granulation tissue, which gradually fills the wound defect, has pronounced signs of inflammation and a complex six-layer structure, described by N.N. Anichkov:

1. superficial leukocyte-necrotic layer

2. superficial layer of vascular loops

3. layer of vertical vessels

4. maturing layer

5. layer of horizontal fibroblasts

6. fibrous layer.

Atrophy(a-exception, trophe-food) – reduction in the volume of cells, tissues, organs with a decrease or cessation of their function. A decrease in the volume of tissues and organs occurs during atrophy due to parenchymal elements. Atrophy must be distinguished from hypoplasia– congenital underdevelopment of organs and tissues.

Atrophy is usually divided into physiological and pathological, local and general.

Physiological atrophy occurs throughout a person's life. Thus, with age, the thymus gland, gonads, bones, and intervertebral cartilage atrophy.

Pathological atrophy occurs due to circulatory disorders, nervous regulation, intoxications, the effects of biological, physical and chemical factors, with malnutrition.

General atrophy manifests itself exhaustion. In this case, there is a pronounced decrease in body weight, dryness and flabbiness. skin. Subcutaneous fat practically absent. There is also no fatty tissue in the greater and lesser omentum, around the kidneys. Its preserved areas have a brown-brown color due to the accumulation of lipochromes. In the liver and myocardium there are signs of brown atrophy with the accumulation of lipofuscin in their cells. Internal organs and endocrine glands are reduced in size.

Distinguish the following types exhaustion: 1.nutritional exhaustion, developing due to starvation or impaired digestion of food; 2. exhaustion with cancer cachexia /most often with cancer of the stomach and other parts of the gastrointestinal tract/; 3. exhaustion due to pituitary cachexia (Simmonds disease due to destruction of the adenohypophysis); 4. exhaustion during cerebral cachexia, which occurs in senile forms of dementia, Alzheimer's and Pick's diseases, due to the involvement of the hypothalamus in the process; 5. exhaustion in other diseases, more often in chronic infections: tuberculosis, chronic dysentery, brucellosis, etc.

The following types of local atrophy are distinguished:

1. Dysfunctional atrophy (from inactivity), resulting from a decrease in organ function due to its lack of demand. An example of such atrophy is muscle atrophy during bone fractures, bone tissue alveolar processes jaws after tooth extraction.

2. Atrophy due to insufficient blood supply - occurs due to narrowing of the lumens of the vessels supplying blood to a given organ or tissue. Examples are: kidney atrophy due to hyalinosis of arterioles in hypertension, brain atrophy due to atherosclerosis of the cerebral arteries.

4. Neurotic atrophy occurs when tissue innervation is impaired due to diseases and damage to the central nervous system and peripheral nerves: atrophy of the soft tissues of the arm due to damage to the brachial nerve, atrophy of the striated muscles in people who have had polio.

1. Atrophy from the action of chemicals and physical factors. Thus, radiation causes atrophy of the bone marrow and gonads. Long-term use ACTH causes atrophy of the adrenal cortex, insulin causes atrophy of the islets of Langerhans of the pancreas.

Atrophied organs are usually reduced in size when examined with the naked eye. Their surface is smooth or granular. When lipofuscin accumulates in an atrophied organ, we speak of brown atrophy, which occurs in the myocardium and liver.

Atrophy on early stages development is a reversible process and if its cause is eliminated, the function of the organ can be restored.

REGENERATION
restoration by the body of lost parts at one or another stage of the life cycle. Regeneration usually occurs in the event of damage or loss of an organ or part of the body. However, in addition to this, restoration and renewal processes constantly occur in every organism throughout its life. In humans, for example, the outer layer of skin is constantly renewed. Birds periodically shed their feathers and grow new ones, and mammals change their fur. Deciduous trees lose leaves every year and are replaced with fresh ones. Such regeneration, usually not associated with damage or loss, is called physiological. Regeneration that occurs after damage or loss of any part of the body is called reparative. Here we will consider only reparative regeneration. Reparative regeneration can be typical or atypical. In typical regeneration, the lost part is replaced by the development of exactly the same part. The cause of the loss may be an external force (for example, amputation), or the animal may deliberately tear off part of its body (autotomy), like a lizard breaking off part of its tail to escape an enemy. With atypical regeneration, the lost part is replaced by a structure that differs from the original quantitatively or qualitatively. The regenerated limb of a tadpole may have fewer fingers than the original one, and a shrimp may grow an antenna instead of an amputated eye.
REGENERATION IN ANIMALS
The ability to regenerate is widespread among animals. Generally speaking, lower animals are more often capable of regeneration than more complex, highly organized forms. Thus, among invertebrates there are many more species capable of restoring lost organs than among vertebrates, but only in some of them is it possible to regenerate an entire individual from a small fragment. Nevertheless general rule the decrease in the ability to regenerate with increasing complexity of the organism cannot be considered absolute. Such primitive animals as ctenophores and rotifers are practically incapable of regeneration, but in much more complex crustaceans and amphibians this ability is well expressed; Other exceptions are known. Some closely related animals differ greatly in this respect. Thus, in an earthworm, a new individual can completely regenerate from a small piece of its body, while leeches are unable to restore one lost organ. In tailed amphibians, a new limb is formed in place of the amputated limb, but in the frog, the stump simply heals and no new growth occurs. Many invertebrates are capable of regenerating large parts of their body. In sponges, hydroid polyps, flatworms, tapeworms and annelids, bryozoans, echinoderms and tunicates, a whole organism can regenerate from a small fragment of the body. Particularly noteworthy is the ability to regenerate in sponges. If the body of an adult sponge is pressed through the mesh tissue, then all the cells will separate from each other, as if sifted through a sieve. If you then put all these individual cells into water and carefully, thoroughly mix, completely destroying all connections between them, then after some time they begin to gradually come closer and reunite, forming a whole sponge, similar to the previous one. This involves a kind of “recognition” at the cellular level, as evidenced by next experiment

. Sponges of three different species were separated into separate cells in the manner described and mixed thoroughly. At the same time, it was discovered that the cells of each species are able to “recognize” the cells of their own species in the total mass and reunite only with them, so that as a result, not one, but three new sponges were formed, similar to the three original ones.

Collier's Encyclopedia. - Open Society. 2000 .

See what "REGENERATION" is in other dictionaries:

REGENERATION- REGENERATION, the process of formation of a new organ or tissue in place of a part of the body that was removed in one way or another. Very often R. is defined as the process of restoring what has been lost, that is, the formation of an organ similar to the removed one. This... ... Big medical encyclopedia

- (late lat., from lat. re again, again, and genus, eris genus, generation). Revival, renewal, restoration of what was destroyed. In a figurative sense: a change for the better. Dictionary foreign words, included in the Russian language... ... Dictionary of foreign words of the Russian language

REGENERATION, in biology, the body’s ability to replace one of the lost parts. The term regeneration also refers to a form of Asexual Reproduction in which a new individual arises from a separated part of the mother's body... Scientific and technical encyclopedic dictionary

Restoration, recovery; compensation, regeneration, renewal, heteromorphosis, pettencoferation, revival, morphallaxis Dictionary of Russian synonyms. regeneration noun, number of synonyms: 11 compensation (20) ... Synonym dictionary

1) restoration, using certain physicochemical processes, of the original composition and properties of waste products for their reuse. In military affairs, air regeneration has become widespread (especially on underwater... ... Marine Dictionary

Regeneration- – returning the used product to its original properties. [Terminological dictionary of concrete and reinforced concrete. FSUE "Research Center "Construction" NIIZHB named after. A. A. Gvozdeva, Moscow, 2007, 110 pp.] Regeneration - restoration of waste... ... Encyclopedia of terms, definitions and explanations of building materials

REGENERATION- (1) restoration of the original properties and composition of waste materials (water, air, oils, rubber, etc.) for their reuse. It is carried out with the help of certain physical chem. processes in special regenerator devices. Wide... ... Big Polytechnic Encyclopedia

- (from Late Lat. regeneratio rebirth renewal), in biology, the restoration by the body of lost or damaged organs and tissues, as well as the restoration of the whole organism from its part. Mostly characteristic of plants and invertebrates... ...

In technology, 1) returning the spent product to its original qualities, for example. restoration of the properties of spent molding sand in foundries, purification of used lubricating oil, transformation of worn rubber products into plastic... ... Big Encyclopedic Dictionary

REGENERATION, regeneration, many. no, female (lat. regeneratio restoration, return). 1. Heating of gas and air entering the furnace with waste combustion products (technical). 2. Reproduction of lost organs by animals (zool.). 3. Radiation... ... Dictionary Ushakova

Surprisingly, if the lizard's tail falls off, the missing part will re-form from the remaining part. In some cases, reparative regeneration is so perfect that the entire multicellular organism is restored from only a small fragment of tissue. Our body spontaneously sheds cells from the surface of the skin and replaces them with newly formed ones. This happens precisely because of regeneration.

Types of regeneration

Reparative regeneration is a natural ability of all living organisms. It is used to replace worn parts, renew damaged and lost fragments, or recreate the body from a small area during the post-embryonic life of the organism. Regeneration is a process that includes growth, morphogenesis and differentiation. Today, all types and types of reparative regeneration are actively used in medicine. This process occurs not only in humans, but also in animals. Regeneration is divided into two types:

• physiological;
• reparative.

There is a constant loss of many structures in our body due to wear and tear. The replacement of these cells is due to physiological regeneration. An example of such a process is the renewal of red blood cells. Worn out skin cells are constantly replaced by new ones.

Reparative regeneration is the process of restoring lost or damaged organs and body parts. IN this type tissues are formed by expansion of adjacent fragments.

• Regeneration of limbs in a salamander.
• Restoring a lost lizard tail.
• Wound healing.
• Replacing damaged cells.

Types of reparative regeneration. Morphallaxis and epimorphosis

Exist Various types reparative regeneration. In our article you can find more detailed information about them. Epimorphic regeneration involves the differentiation of adult structures to form an undifferentiated mass of cells. It is with this process that the recovery of a deleted fragment is associated. An example of epimorphosis is the regeneration of limbs in amphibians. In the morphallaxis type, regeneration occurs mainly due to the rearrangement of existing tissues and the restoration of boundaries. An example of such a process is the formation of a hydra from a small fragment of its body.

Reparative regeneration and its forms

Recovery occurs due to the spread of neighboring tissues, which fill with young cells with a defect. Subsequently, full-fledged mature fragments are formed from them. Such forms of reparative regeneration are called restoration.

There are two options for this process:

• The loss is compensated by fabric of a similar type.
• The defect is replaced with new tissue. A scar forms.

Bone tissue regeneration. New method

In the modern medical world, reparative bone tissue regeneration is a reality. This technique is most often used in bone graft surgery. It is worth noting that to collect sufficient quantity material for such a procedure is incredibly difficult. Fortunately, a new surgical method for repairing damaged bones has emerged.

Thanks to biomimicry, researchers have developed a new method for restoring bone structure. Its main purpose is to use sea sponge corals as scaffolds or frames for bone tissue. Thanks to this, damaged fragments will be able to repair themselves. Corals are ideal for this type of surgery because they integrate easily into existing bones. Their structure also coincides in terms of porosity and composition.

The process of restoring bone tissue using corals

To restore using the new method, surgeons must prepare coral or sea sponges. They also need to select substances such as stromal or bone marrow, which are capable of becoming any other adamantoblast in the body. Reparative tissue regeneration is a rather labor-intensive process. During the operation, sponges and cells are inserted into a section of damaged bone.

Over time, the bone fragments either regenerate or the stem adamantoblasts expand the existing tissue. Once the bone fuses, the coral or becomes part of it. This is due to their similarity in structure and composition. Reparative regeneration and methods for its implementation are being studied by specialists from all over the world. It is thanks to this process that you can cope with some acquired deficiencies of the body.

Epithelial restoration

Methods of reparative regeneration play an important role in the life of any living organism. Transitional epithelium is a multilayered covering that is characteristic of urinary drainage organs such as the bladder and kidneys. They are most susceptible to sprains. It is in them that tight junctions are located between the cells, which prevent the penetration of fluid through the wall of the organ. The adamanthoblasts of the urinary drainage organs quickly wear out and weaken. Reparative regeneration of epithelium occurs due to the content of stem cells in the organs. They retain the ability to divide throughout their entire life cycle. Over time, the update process deteriorates significantly. This is associated with numerous diseases that occur in many people as they age.

Mechanisms of reparative regeneration of the skin. Their influence on the recovery of the body after burn injuries

It is known that burns are the most common injury among children and adults. Today the topic of such injuries is extremely popular. It is no secret that burn injuries can not only leave a scar on the body, but also cause surgical intervention. To date, there is no such procedure that would completely get rid of the resulting scar. This is due to the fact that the mechanisms of reparative regeneration are not fully understood.

There are three degrees of burn injuries. It is known that more than 4 million people suffer from skin damage caused by exposure to steam, hot water or chemical substance. It's worth noting that scarred skin is not the same as the skin it replaces. It also differs in its functions. The newly formed tissue is weaker. Today, experts are actively studying the mechanisms of reparative regeneration. They believe that they will soon be able to completely rid patients of burn scars.

Level of reparative regeneration of bone tissue. Optimal conditions for the process

Reparative regeneration of bone tissue and its level are determined by the degree of damage in the fracture area. The more microcracks and injuries, the slower the formation of callus will occur. It is for this reason that experts prefer treatment methods that are not associated with causing additional damage. The most optimal conditions for reparative regeneration in bone fragments are immobility of the fragments and slow distraction. If they are absent, connective fibers are formed at the fracture site, which subsequently form

Pathological regeneration

Physical and reparative regeneration plays an important role in our lives. It is no secret that for some this process may be slowed down. What is this connected with? You can find out this and much more in our article.

Pathological regeneration is a violation of recovery processes. There are two types of such recovery - hyperregeneration and hyporegeneration. The first process of formation of new tissue is accelerated, and the second is slow. These two types are a violation of regeneration.

The first signs of pathological regeneration are the formation of long-term healing injuries. Such processes arise as a consequence of disruption of local conditions.

How to speed up the process of physiological and reparative regeneration

Physiological and reparative regeneration plays an important role in the life of every living creature. Examples of such a process are known to absolutely everyone. It is no secret that some patients have injuries that take a long time to heal. Any living organism must have a complete diet, which includes a variety of vitamins, microelements and nutrients. With a lack of nutrition, energy deficiency occurs and trophic processes are disrupted. As a rule, patients develop one or another pathology.

To speed up the regeneration process, it is necessary to first remove dead tissue and take into account other factors that may affect recovery. These include stress, infections, dentures, lack of vitamins, and much more.

To speed up the regeneration process, a specialist may prescribe a vitamin complex, anabolic agents and biogenic stimulants. IN home medicine actively used sea ​​buckthorn oil, carotoline, as well as juices, tinctures and decoctions of medicinal herbs.

Shilajit to speed up regeneration

Reparative regeneration includes complete or partial restoration of damaged tissues and organs. Does this process speed up the mummy? What it is?
It is known that mumiyo has been used for 3 thousand years. It's biological active substance which flows out of rock crevices southern mountains. Its deposits are found in more than 10 countries around the world. Shilajit is a sticky mass dark brown. The substance dissolves well in water. Depending on the place of collection, the composition of the mummy may differ. Nevertheless, absolutely each of them contains a vitamin complex, a number of minerals, essential oils and bee venom. All these components contribute to the rapid healing of wounds and injuries. They also improve the body's response to adverse conditions. Unfortunately, there is no drug based on mumiyo to accelerate regeneration, since the substance is difficult to process.

Regeneration in animals. general information

As we said earlier, the regeneration process occurs in absolutely any living organism, including animals. It is worth noting that the higher it is organized, the worse the recovery takes place in its body. In animals, reparative regeneration is the process of reproducing lost or damaged organs and tissues. The simplest organisms restore their body only in the presence of a nucleus. If it is missing, then the lost parts are not reproduced.

There is an opinion that siskins can restore their limbs. However, this information has not been confirmed. Mammals and birds are known to repair only tissue. However, the process has not been fully studied.
The easiest way for animals to recover is nervous and muscle. In most cases, new fragments are formed from the remains of old ones. A significant increase in regenerating organs has been observed in amphibians. A similar thing occurs in lizards. For example, instead of one tail, two grow.

After conducting a number of studies, scientists have proven that if a lizard’s tail is cut off obliquely and in doing so touches not one, but two or more spines, then the reptile will grow 2-3 tails. There are also cases when an animal may recover an organ not where it was previously located. Surprisingly, through regeneration, an organ can also be recreated that was not previously in the body of a particular creature. This process is called heteromorphosis. All methods of reparative regeneration are extremely important not only for mammals, but also for birds, insects, and unicellular organisms.

Let's sum it up

Each of us knows that lizards can easily completely restore their tail. Not everyone knows why this happens. Physiological and reparative regeneration plays an important role in everyone's life. To restore it you can use: medications, and home methods. Mumiyo is considered one of the best remedies. It not only speeds up the regeneration process, but improves the overall background of the body. Be healthy!

Regeneration(from Latin regeneratio - rebirth) - the process of restoration by the body of lost or damaged structures. Regeneration maintains the structure and functions of the body, its integrity. There are two types of regeneration: physiological and reparative. The restoration of organs, tissues, cells or intracellular structures after their destruction during the life of the body is called physiological regeneration. Restoration of structures after injury or other damaging factors is called reparative regeneration. During regeneration, processes such as determination, differentiation, growth, integration, etc. occur, similar to the processes that take place in embryonic development. However, during regeneration, they all come secondarily, i.e. in a formed organism.

Physiological regeneration is the process of updating the functioning structures of the body. Thanks to physiological regeneration, structural homeostasis is maintained and the organs can constantly perform their functions. From a general biological point of view, physiological regeneration, like metabolism, is a manifestation of such an important property of life as self-renewal.

An example of physiological regeneration at the intracellular level is the processes of restoration of subcellular structures in the cells of all tissues and organs. Its significance is especially great for the so-called “eternal” tissues that have lost the ability to regenerate through cell division. This primarily applies to nervous tissue.

Examples of physiological regeneration at the cellular and tissue levels are the renewal of the epidermis of the skin, the cornea of ​​the eye, the epithelium of the intestinal mucosa, peripheral blood cells, etc. The derivatives of the epidermis are renewed - hair and nails. This is the so-called proliferative regeneration, i.e. replenishment of the number of cells due to their division. In many tissues there are special cambial cells and foci of their proliferation. These are crypts in the epithelium of the small intestine, bone marrow, proliferative zones in the epithelium of the skin. The intensity of cellular renewal in these tissues is very high. These are the so-called “labile” tissues. All red blood cells of warm-blooded animals, for example, are replaced in 2-4 months, and the epithelium of the small intestine is completely replaced in 2 days. This time is required for the cell to move from the crypt to the villus, perform its function and die. Cells of organs such as the liver, kidney, adrenal gland, etc., renew themselves much more slowly. These are the so-called “stable” fabrics.

The intensity of proliferation is judged by the number of mitoses per 1000 counted cells. If we consider that mitosis itself lasts on average about 1 hour, and the entire mitotic cycle in somatic cells lasts on average 22-24 hours, then it becomes clear that in order to determine the intensity of renewal of the cellular composition of tissues it is necessary to count the number of mitoses over one or several days . It turned out that the number of dividing cells is not the same at different times of the day. So it was opened daily rhythm of cell divisions, an example of which is shown in Fig. 8.23.

Rice. 8.23. Daily changes in the mitotic index (MI)

in the epithelium of the esophagus ( I) and cornea ( 2 ) mice.

The mitotic index is expressed in ppm (0 / 00), reflecting the number of mitoses

per thousand cells counted

A daily rhythm in the number of mitoses was found not only in normal but also in tumor tissues. It is a reflection of more general pattern, namely the rhythm of all body functions. One of the modern areas of biology is chronobiology - studies, in particular, the mechanisms of regulation of daily rhythms of mitotic activity, which has a very important for medicine. The existence of a daily periodicity in the number of mitoses indicates the adjustability of physiological regeneration by the body. In addition to daily allowances, there are lunar and annual cycles of tissue and organ renewal.

There are two phases in physiological regeneration: destructive and restorative. It is believed that the breakdown products of some cells stimulate the proliferation of others. Hormones play a major role in regulating cellular renewal.

Physiological regeneration is inherent in organisms of all species, but it occurs especially intensively in warm-blooded vertebrates, since they generally have a very high intensity of functioning of all organs compared to other animals.

Reparative(from Latin reparatio - restoration) regeneration occurs after damage to a tissue or organ. It is very diverse in terms of the factors causing damage, the amount of damage, and the methods of recovery. Mechanical trauma, such as surgery, action toxic substances, burns, frostbite, radiation exposure, fasting, and other pathogenic agents - all these are damaging factors. Regeneration after mechanical trauma has been most widely studied. The ability of some animals, such as hydra, planaria, some annelids, starfish, sea squirts, etc., to restore lost organs and parts of the body has long amazed scientists. Charles Darwin, for example, considered amazing the ability of a snail to reproduce a head and the ability of a salamander to restore eyes, tail and legs exactly in those places where they were cut off.

The extent of damage and subsequent recovery varies widely. An extreme option is to restore the whole organism from a separate small part of it, actually from a group of somatic cells. Among animals, such restoration is possible in sponges and coelenterates. Among plants, the development of a whole new plant is possible even from one somatic cell, as was obtained with the example of carrots and tobacco. This type of restoration processes is accompanied by the emergence of a new morphogenetic axis of the body and is called B.P. Tokin “somatic embryogenesis”, for in many ways it resembles embryonic development.

There are examples of restoration of large areas of the body consisting of a complex of organs. Examples include the regeneration of the oral end in the hydra, the cephalic end in the annelid, and the restoration of the starfish from a single ray (Fig. 8.24). Regeneration of individual organs is widespread, for example, the limbs of a newt, the tail of a lizard, and the eyes of arthropods. Healing of skin, wounds, damage to bones and other internal organs is a less extensive process, but no less important for restoring the structural and functional integrity of the body. Of particular interest is the ability of embryos at early stages of development to recover after significant loss of material. This ability was the last argument in the struggle between supporters of preformationism and epigenesis and led G. Driesch to the concept of embryonic regulation in 1908.

Rice. 8.24. Regeneration of a complex of organs in some species of invertebrate animals. A - hydra; B - ringworm; IN - Starfish

(see text for explanation)

There are several varieties or methods of reparative regeneration. These include epimorphosis, morphallaxis, healing of epithelial wounds, regenerative hypertrophy, compensatory hypertrophy.

Epithelialization When healing wounds with damaged epithelial cover, the process is approximately the same, regardless of whether organ regeneration further occurs through epimorphosis or not. Epidermal wound healing in mammals, when the wound surface dries to form a crust, proceeds as follows (Fig. 8.25). The epithelium at the edge of the wound thickens due to an increase in cell volume and expansion of intercellular spaces. The fibrin clot plays the role of a substrate for the migration of the epidermis into the depths of the wound. Migrating epithelial cells do not undergo mitosis, but they have phagocytic activity. Cells from opposite edges come into contact. Then comes keratinization of the wound epidermis and separation of the crust covering the wound.

Rice. 8.25. Diagram of some of the events taking place

during epithelization of a skin wound in mammals.

A- the beginning of ingrowth of the epidermis under the necrotic tissue; B- fusion of the epidermis and separation of the scab:

1 -connective tissue, 2- epidermis, 3- scab, 4- necrotic tissue

By the time the epidermis meets opposite edges, a burst of mitosis is observed in the cells located immediately around the edge of the wound, which then gradually declines. According to one version, this outbreak is caused by a decrease in the concentration of the mitotic inhibitor - kaylon.

Epimorphosis is the most obvious method of regeneration, consisting in the growth of a new organ from the amputation surface. Limb regeneration of newts and axolotls has been studied in detail. There are regressive and progressive phases of regeneration. Regressive phase begin with healing wound, during which the following main events occur: stopping bleeding, contraction of the soft tissue of the limb stump, formation of a fibrin clot over the wound surface and migration of the epidermis covering the amputation surface.

Then it begins destruction osteocytes at the distal end of the bone and other cells. Simultaneously in the destroyed soft fabrics cells involved in inflammatory process, phagocytosis and local edema are observed. Then, instead of forming a dense plexus of connective tissue fibers, as occurs during wound healing in mammals, differentiated tissue is lost in the area under the wound epidermis. Characterized by osteoclastic bone erosion, which is a histological sign dedifferentiation. The wound epidermis, already penetrated by regenerating nerve fibers, begins to quickly thicken. The spaces between tissues are increasingly filled with mesenchymal-like cells. The accumulation of mesenchymal cells under the wound epidermis is the main indicator of the formation of regenerative blastemas. The blastema cells look the same, but it is at this moment that the main features of the regenerating limb are laid down.

Then it begins progressive phase, which is most characterized by the processes of growth and morphogenesis. The length and weight of the regenerative blastema rapidly increase. The growth of the blastema occurs against the background of the formation of limb features in full swing, i.e. its morphogenesis. When the general shape of the limb has already developed, the regenerate is still smaller than the normal limb. The larger the animal, the greater this difference in size. The completion of morphogenesis requires time, after which the regenerate reaches the size of a normal limb.

Some stages of forelimb regeneration in a newt after amputation at the shoulder level are shown in Fig. 8.26. The time required for complete limb regeneration varies depending on the size and age of the animal, as well as the temperature at which it occurs.

Rice. 8.26. Stages of forelimb regeneration in newt

In young axolotl larvae, a limb can regenerate in 3 weeks, in adult newts and axolotls in 1-2 months, and in terrestrial ambistos this takes about 1 year.

During epimorphic regeneration, an exact copy of the removed structure is not always formed. This regeneration is called atypical. There are many types of atypical regeneration. Hypomorphosis - regeneration with partial replacement of the amputated structure. Thus, in an adult clawed frog, an awl-like structure appears instead of a limb. Heteromorphosis - the appearance of another structure in place of the lost one. This can manifest itself in the form of homeotic regeneration, which consists in the appearance of a limb in place of the antennae or eyes in arthropods, as well as in a change in the polarity of the structure. From a short fragment of planaria, a bipolar planaria can be reliably obtained (Fig. 8.27).

Formation of additional structures occurs, or excessive regeneration. After cutting the stump when amputating the head section of the planarian, regeneration of two or more heads occurs (Fig. 8.28). Available more fingers when regenerating an axolotl limb, turning the end of the limb stump by 180°. Additional structures are mirror images of the original or regenerated structures next to which they are located (Bateson's law).

Rice. 8.27. Bipolar planaria

Morphallaxis - This is regeneration by restructuring the regenerating area. An example is the regeneration of a hydra from a ring cut from the middle of its body, or the restoration of a planaria from one tenth or twentieth of its part. In this case, no significant shaping processes occur on the wound surface. The cut piece shrinks, the cells inside it rearrange, and a whole individual appears

reduced in size, which then grows. This method of regeneration was first described by T. Morgan in 1900. In accordance with his description, morphallaxis occurs without mitosis. There is often a combination of epimorphic growth at the amputation site with reorganization through morphallaxis in adjacent parts of the body.

Rice. 8.28. Multi-headed planaria obtained after head amputation

and applying notches to the stump

Regenerative hypertrophy refers to internal organs. This method of regeneration involves increasing the size of the remaining organ without restoring its original shape. An illustration is the regeneration of the liver of vertebrates, including mammals. With a marginal injury to the liver, the removed part of the organ is never restored. The wound surface is healing. At the same time, cell proliferation (hyperplasia) increases inside the remaining part, and within two weeks after removal of 2/3 of the liver, the original weight and volume are restored, but not the shape. The internal structure of the liver appears to be normal, the lobules have a typical size. Liver function also returns to normal.

Compensatory hypertrophy consists of changes in one of the organs with a violation in another, belonging to the same organ system. An example is hypertrophy in one of the kidneys when the other is removed or enlargement of the lymph nodes when the spleen is removed.

The last two methods differ in the location of regeneration, but their mechanisms are the same: hyperplasia and hypertrophy.

Restoration of individual mesodermal tissues, such as muscle and skeletal tissue, is called tissue regeneration. For muscle regeneration, it is important to preserve at least small stumps at both ends, and for bone regeneration, periosteum is necessary. Regeneration by induction occurs in certain mesodermal tissues of mammals in response to the action of specific inducers that are introduced into the damaged area. This method makes it possible to completely replace the defect of the skull bones after introducing bone filings into it.

So there are many in various ways or types of morphogenetic phenomena during the restoration of lost and damaged parts of the body. The differences between them are not always obvious, and a deeper understanding of these processes is required.

The study of regeneration phenomena concerns not only external manifestations. There are a number of issues that are problematic and theoretical in nature. These include questions of regulation and conditions in which restoration processes take place, questions of the origin of cells involved in regeneration, the ability to regenerate in various groups, animals and features of recovery processes in mammals.

It has been established that real changes in electrical activity occur in the limbs of amphibians after amputation and during the process of regeneration. When an electric current is passed through an amputated limb, adult clawed frogs exhibit increased forelimb regeneration. In the regenerates, the amount of nervous tissue increases, from which it is concluded that the electric current stimulates the ingrowth of nerves into the edges of the limbs, which do not normally regenerate.

Attempts to stimulate limb regeneration in mammals in a similar way have been unsuccessful. Thus, under the influence of an electric current or by combining the action of an electric current with a nerve growth factor, it was possible to obtain in rats only the growth of skeletal tissue in the form of cartilaginous and bone calluses, which did not resemble normal elements of the skeleton of the limbs.

There is no doubt that regeneration processes are regulated by nervous system. When the limb is thoroughly denervated during amputation, epimorphic regeneration is completely suppressed and a blastema never forms. Interesting experiments were carried out. If the nerve of a newt's limb is retracted under the skin of the base of the limb, an additional limb is formed. If it is taken to the base of the tail, the formation of an additional tail is stimulated. Reduction of the nerve to the lateral region does not cause any additional structures. These experiments led to the creation of the concept regeneration fields. .

It was found that the number of nerve fibers. The type of nerve does not matter. The influence of nerves on regeneration is associated with the trophic effect of nerves on the tissues of the limbs.

Data received in favor humoral regulation regeneration processes. A particularly common model to study this is the regenerating liver. After administration of serum or blood plasma from animals that had undergone liver removal to normal intact animals, stimulation of the mitotic activity of liver cells was observed in the former. In contrast, when injured animals were given serum from healthy animals, a decrease in the number of mitoses in the damaged liver was obtained. These experiments may indicate both the presence of regeneration stimulators in the blood of injured animals and the presence of cell division inhibitors in the blood of intact animals. Explaining the results of the experiments is complicated by the need to take into account the immunological effect of the injections.

The most important component of the humoral regulation of compensatory and regenerative hypertrophy is immunological response. Not only partial removal organ, but many influences cause disturbances in the immune status of the body, the appearance of autoantibodies and stimulation of cell proliferation processes.

There is great disagreement on the issue of cellular sources regeneration. Where do undifferentiated blastema cells, morphologically similar to mesenchymal cells, come from or how do they arise? There are three assumptions.

1. Hypothesis reserve cells implies that the precursors of the regenerative blastema are the so-called reserve cells, which stop at some early stage of their differentiation and do not participate in the development process until they receive a stimulus for regeneration.

2. Hypothesis temporary dedifferentiation, or modulation of cells suggests that in response to a regenerative stimulus, differentiated cells can lose signs of specialization, but then differentiate again into the same cell type, i.e., having temporarily lost specialization, they do not lose determination.

3. Hypothesis complete dedifferentiation specialized cells to a state similar to mesenchymal cells and with possible subsequent transdifferentiation or metaplasia, i.e. transformation into cells of another type, believes that in this case the cell loses not only specialization, but also determination.

Modern research methods do not allow us to prove all three assumptions with absolute certainty. However, it is absolutely true that in the stumps of the axolotl digits, chondrocytes are released from the surrounding matrix and migrate into the regenerative blastema. Their further fate is not determined. Most researchers recognize dedifferentiation and metaplasia during lens regeneration in amphibians. The theoretical significance of this problem lies in the assumption of the possibility or impossibility of a cell changing its program to such an extent that it returns to a state where it is again able to divide and reprogram its synthetic apparatus. For example, a chondrocyte becomes a myocyte or vice versa.

The ability to regenerate does not have a clear dependence on organization level, although it has long been noticed that lower organized animals have a better ability to regenerate external organs. This is confirmed by amazing examples of regeneration of hydra, planarians, annelids, arthropods, echinoderms, and lower chordates, such as ascidians. Among vertebrates, tailed amphibians have the best regenerative ability. It is known that different types of the same class can differ greatly in their ability to regenerate. In addition, when studying the ability to regenerate internal organs, it turned out that it is significantly higher in warm-blooded animals, such as mammals, compared to amphibians.

Regeneration mammals is unique. For the regeneration of some external organs, special conditions are required. The tongue and ear, for example, do not regenerate with marginal damage. If you apply a through defect through the entire thickness of the organ, recovery goes well. In some cases, nipple regeneration was observed even after amputation at the base. Regeneration of internal organs can be very active. An entire organ is restored from a small fragment of the ovary. The features of liver regeneration have already been discussed above. Various mammalian tissues also regenerate well. There is an assumption that the impossibility of regeneration of limbs and other external organs in mammals is adaptive in nature and is due to selection, since with an active lifestyle, delicate morphogenetic processes would make existence difficult. Achievements of biology in the field of regeneration are successfully applied in medicine. However, there are many unresolved issues in the regeneration problem.