Biological effects of glucocorticoids
Endocrinology / / April 28, 2016
The biological effect of hormones of the adrenal cortex
Biological effects of glucocorticoid. Cortisol and corticosterone have in many respects similar biological effect on the body.However, unlike corticosterone cortisol does not have anti-inflammatory effect, not cause-eosin and has a great singing mineralocorticoid effect.Corticosterone plays a small role in the regulation of metabolic processes in humans, and the main glucocorticoid is cortisol.
Cortisone has the same biological properties as cortisol, giving him in several activity.
One of the important aspects of the metabolic action of cortisol is its ability to stimulate gluconeogenesis.Under the influence of cortisol increases the amount of glycogen in the liver and muscles, and blood sugar.Starting materials in the synthesis of carbohydrates and amino acids are fatty acids.In the synthesis of amino acids from carbohydrates oxidative deamination occurs and transamination of amino acids with the formation of pyruvic acid.The latter can be
In the early days steroid therapy glucose tolerance is lowered, but on subsequent days due to hypertrophy (i-cells of the islets of the pancreas and an increased production of insulin in response to increased production of carbohydrates it normalizes Subsequently prolonged excess blood circulating cortisol both endogenous. -the syndrome pituitary - Cushing - and inputted externally may come depletion of islet pancreatic apparatus developmental steroid diabetes essential feature steroid diabetes is rare ketoacidosis with it, and that the amount of glycogen in the liver with diabetes as not reduced.and increases
ketonemia that occurs during fasting, healthy people under the influence of cortisol is reduced in patients with diabetes -. increases
There is evidence that under the influence of cortisol may decrease the renal permeability of glucose threshold in connection with the increase of its filtration in the glomeruli.glycosuria leading to under normal blood sugar level.
Cortisol has a catabolic (or antianabolicheskoe) action.Increased deamination of amino acids leads to increased nitrogen excretion in urine.in peripheral blood protein decreases.There is a rapid exchange of plasma albumin - faster his education and increased decay.
cortisol effect on protein metabolism in different tissues differently.Under the influence of the amount of cortisol in the protein and muscle tissue was connector is reduced in the liver - increase.Antianabolicheskoe action of cortisol is associated with inhibition of penetration of amino acids into the cell in the microsomal level.
With catabolic action of cortisol are associated depletion of proteins, swelling and muscle atrophy and osteoporosis due to bone resorption protein bases observed with prolonged excess of cortisol.Cortisol inhibits the development of epiphyseal cartilage, being in this respect, the growth hormone antagonist.
mostly content of free amino acids in muscle tissue and increases in the blood, liver and kidney - decreases.Increased allocation of amino acids in the urine.
Cortisol increases the fat content in the body.This effect is associated with increased production of carbohydrates.Increased intake of glucose in the blood stimulates the insular apparatus that apparently promotes the deposition of fat.What matters is the ability of cortisol increases appetite.A characteristic feature of cortisol is that it causes a kind of redistribution of fat in the subcutaneous adipose tissue: a preferential deposition of the head, neck, face, or with a relatively thin limbs completely.Prolonged cortisol excess is observed hyperlipidemia and hypercholesterolemia.
Cortisol increases the filtration rate in the kidney glomeruli, inhibits the release of vasopressin in the blood and reduces the sensitivity of the renal tubule to the action of vasopressin, thus lowering the water reabsorption in the kidney tubules.Under the influence of cortisol and increased inulin clearance of urea.
Cortisol promotes retention in the body of sodium ions, stimulating its reabsorption in the tubules.Allocation of potassium ions under the influence of cortisol rises, which binds to the active excretion of these ions tubule cells.The ability to delay the body's sodium to a much greater extent than cortisol, another characteristic of adrenal hormones - aldosterone.
sodium delay comes at the beginning of the use of cortisol can with continued his introduction replaced by a sharp increase in sodium excretion in the urine.This phenomenon is associated with an increase in glomerular filtration.
Cortisol increases the content of the extracellular fluid and reduces the amount of intracellular fluid.
reabsorption of calcium and phosphorus ions under the influence of cortisol decreases, the allocation of urine increases.Increased urinary excretion of calcium may contribute to the formation of kidney stones.
Cortisol promotes renal excretion of uric acid, lowering the concentration of the latter in the blood.
Isolation urine pepsin under the influence of cortisol increases, which seems to be associated with increased production of pepsin of the gastric mucosa cells.
Cortisol promotes the lysis of lymphocytes, fixed in the lymph nodes and other organs and tissues.The number of lymphocytes circulating in the blood, thereby decreasing an excess cortisol.
number of circulating eosinophils under the influence of cortisol also decreases.
Cortisol has a stimulating effect on bone marrow hematopoiesis, especially in the production of neutrophils.In this regard, the total number of leukocytes in the blood increases with excess cortisol by neutrophils and may reach 12-20 thousand. 1 mm3.The stimulating effect of cortisol on medullary hematopoiesis also seen an increase in the production of red blood cells and platelets.
Cortisol increases brain electroexcitability that may be due to the accumulation of ammonia in the brain, changes the conditioned reflex activity.
Cortisol increases the acidity of gastric juice and increases the production of pepsin.Isolation increases uropepsina urine.Apparently, due to increased gastric digestive ability, but also in connection with antianabolicheskim action when administered glucocorticoid cortisol tendency to the formation of gastric erosions and ulcers and bleeding in the lower gastrointestinal tract ulceration and perforation.
Cortisol helps to increase blood pressure.This is its effect is partly due to mineralocorticoid effect: the delay of sodium ions sensitizing blood vessels to the pressor effects.Specific glikokortikoidnoe the effect of cortisol on vascular tone is reduced to vessels sensitization to noradrenaline pressor action.
data on the effect of cortisol in the blood cholesterol are contradictory, and there are indications that cortisol inhibits deposition of cholesterol in the vascular wall.
With the influence of cortisol in the mesenchymal tissue and its derivatives is mainly due to anti-inflammatory hormone, often used for medicinal purposes.The higher than normal levels of cortisol reduces the acute inflammatory response, reducing exudation and migration of cells.Cortisol inhibits the activity of hyaluronidase, inhibits hyperergic response to the antigen - antibody inhibits the intracellular synthesis of histamine.Brakes also reparative phase of the inflammatory process.Reduces the number of mitosis, suppresses the formation of fibroblasts.There degeneration of collagen fibers.The amount of collagen in the connective tissue decreases.Wound healing under the influence of excess cortisol is inhibited.
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- blood supply and innervation of the adrenal
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- physiology of the pineal gland and its relationship with the endocrine glands
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phagocytosis under the influence of cortisol does not change significantly.
In very high doses, several times higher than the physiological level, cortisol inhibits the synthesis of antibodies.Data on the effect of smaller amounts of cortisol in the body's immune system is contradictory.
In addition to these side effects on cortisol metabolism, to identify the most part under administration to large amounts of the hormone or increased production of its own by the adrenal cortex, great physiological 'important causes, or permissive action of cortisol.Under permissive effect of cortisol causes or realize the property of the hormone at the minimum level to ensure the flow of some physiological reactions.To some effects, such trauma may cause certain metabolic shifts in the body requires a small amount of cortisol, which in itself does not cause a similar effect.
It is suggested that the biological effect of excess or deficiency of cortisol can not only quantitatively but also qualitatively different from the effect of physiological amounts of this hormone.