CHOLECYSTOKININ

From Big Medical Encyclopedia

CHOLECYSTOKININ (vulture. pancreozymin) — the hormone of the person and animals participating in humoral regulation of secretory and motor functions went. - kish. path. Cholecystokinin is a part so-called enterinovy (intestinal hormonal) systems and along with other hormones participates in control of consecutive inclusion of digestive processes, and also in regulation of function of the vegetative centers of a hypothalamus and feeding behavior in general.

Hormone is discovered in 1928 by Ivy (A. S. Ivy) and Oldberg (E. Old-berg) in extracts of a mucous membrane of proximal departments of a small bowel of a dog as the factor causing at introduction to blood of reduction of a gall bladder (see). In 1943 Mr. A. Harper and Reyper (N. S. Kareg) reported about allocation from extracts of a duodenum of a pig of other hormone which is stimulating release of enzymes from a pancreas other than secretin (see) and received the name «pancreozymin». Only in 1964 Mr. V. Mutt, having received high cleaning drugs of cholecystokinin, proved that cholecystokinin and pancreozymin — the same hormone cosecreted by I-cells of a mucous membrane of a duodenum and proximal department of a small bowel in response to irritation decomposition products of proteins and fats. In a mucous membrane of intestines 3 molecular forms of hormone differing on number of the amino-acid remains (cholecystokinin-8, cholecystokinin-12 and cholecystokinin-33) are revealed. From them the greatest share is the share of cholecystokinin-8 (60 — 70% of the general contents); ho-letsistokinin-33 and cholecystokinin-12 make approximately 15%. Cholecystokinin-33 has the following amino-acid structure: Lise-is scarlet is Pro-Ser-Gli-Arg-Val-Ser-Met-Ile - L of Iz-Asn-L of Ey-Gln-Ser-L ey-Asp-I

i Missile defense - It is gray - Gis-Arg-Ile-Ser-Asp-Arg-Asp-the Shooting gallery - (S03H) - Met-Gli-Tri-Met-Asi-Fen-XH2. For manifestation by hormone biol. presence of the sulphated rest of tyrosine is important action. Splitting of peptide bonds of Apr21 — Ile22, Apr25 — Asp26 (it is shown on you-sheprivodimoy to a formula by shooters) enzymes leads to formation of cholecystokinin-12 and holetsistoki-nina-8. At healthy people the content of hormone in blood makes 400 — 800 ml of ml and increases after meal to 1000 — 1200 ml of ml. Destruction of hormone happens preferential in blood and a pancreas (at dogs the period of biological half-decay of hormone makes 1,8+0,75 min.). From blood hormone through kidneys can get to urine, keeping at the same time hormonal activity (urokholetsis-tokinin). Content of cholecystokinin in fabrics and biol. liquids determine by a radio immunological method (see).

Fiziol. effects of hormone on went. - kish. a path are various: reduction and emptying of a gall bladder and sphincteri incontinence of Aude-di; stimulation of biliary secretion liver, pancreatic enzymes and bicarbonates an exocrine part of a pancreas (see), strengthening of secretion of insulin and a glucagon endocrine cells of a pancreas, braking of gastric emptying (see), stimulation of a vermicular movement of a small bowel (see Intestines), increase in secretion salt to - you in a stomach and competitive inhibition of secretion salt to - you, caused by gastrin (see), braking of absorption of water and electrolytes from a jejunum. Disturbance of secretion of hormone can be one of pathogenetic mechanisms of obesity, and also disorders of secretory and motor functions went. - kish. a path at different types of its pathology. Assume what to lay down. action of cholagogue means is connected with stimulation of secretion of cholecystokinin.

In the 70th 20 century were established that cholecystokinin is synthesized not only in intestines, but also in neurons of the central and peripheral nervous system. The first data on it appeared in 1975 when J. J. Vanderhaeghen with sotr. found in a brain of the person and animals a gastrinpo-dobny immunoreactivity, edges as proved in 1977 to G. J. Dockray, it is generally caused by presence of the peptides close on a structure to cholecystokinin, but not to gastrin. The greatest number of holetsistokininsinteziruyu-shchy neurons is revealed in bark of big hemispheres, limbic system and a back share of a hypophysis. In a brain also specific hormone receptors, concentration to-rykh most above are found in bark of big hemispheres, a kernel having a tail and an olfactory bulb. Studying of the central effect of cholecystokinin is on a stage of experiments so far. Believe that the main role of this hormone in a nervous system is connected with regulation of appetite. In a functional power supply system it, apparently, carries out a role of hormone of saturation. The sating effect of hormone is implemented both on central, and on peripheral levels; peripheral action is explained with activation of afferent fibers of gastric branches of a vagus nerve. At administration of hormone (cholecystokinin-8) in cerebral cavities of experimental animals in addition to effect of saturation other central effects are observed: hyperglycemia, hypothermia, analgesia, change of release of anterior pituitary hormones. It is suggested about a mediator and modulator role of cholecystokinin in a nervous system. Point such facts as vnutrineyroialny localization of cholecystokinin, release of peptide in response to depolarization of nerve fibrils, existence of specific receptors, ability of hormone to activate nervous cells, etc.

See also Digestion to it.

Bibliography: To l and m about in P. K. Peptides and alimentary system, L., 1983; T and-mofeeval. Century, etc. Influence of octapeptide of cholecystokinin on the level of monoamines of a brain in the conditions of food and drinking motivational vozbuzhdeniye, Zhurn. vyssh. nervn. deyateln., t. 33, No. 5, page 936, 1983; At about l e in A. M. Enterinovaya (intestinal hormonal) system, L., 1978; Physiology of digestion, under the editorship of. 'A. V. Solovyova, L., 1974; F e k e t e M. and. lake of Effect of cholecystokinin on self-stimulation behavior in rats, Europ. J. Pharmacol., v. 91, p. 77, 1983; I v at A. S. and. About 1 D-Kommersant e r g E. Hormone mechanism for gallbladder contraction and evacuation, Amer. J. Physiol., v. 86, p. 599, 1928;

Smith G. P. a. o. Abdominal vagotomy blocks the satiety effect of cholecystokinin in the rat, Science, v. 213, p. 1036, 1981; Snyder S. H. a. InnisR. B. Peptide neurotrans-mitters, Ann. Rev. Biochem., v. 48, p. 755, 1979; VanderhaeghenJ. J. a. o. Immunohistochemical localization of chole-cystokinin-and gastrin-like peptides in the brain and hypophysis of the rat, Proc. nat. Acad. Sci. (Wash.), v. 77, p. 1 190, 1980.

M. M. Polesskaya.

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