Biological effects of catecholamines
Endocrinology / / April 30, 2016
The biological effect of hormones of the adrenal cortex
Adrenaline has a significant impact mainly in the heart, increases contractility, excitability and conduction myocardium.Heart rate, their strength, systolic and minute volume of blood under the influence of adrenalin increases systolic and pulse pressure - is increased.With an excess of adrenaline can occur arrhythmia and even ventricular fibrillation.The increased amount of adrenaline can cause a violation of the oxidative processes in the heart muscle;at the same time, despite the increase in oxygen supply, its use is hampered by the myocardium.May develop significant metabolic disorders in the myocardium, resulting in dystrophic changes in it.Norepinephrine
affects the heart in less than adrenaline, acting essentially in the same directions as the latter.Unlike epinephrine, norepinephrine reduces the heart rate.
catecholamines have different effects on the tone of the various vessels.As adrenaline and noradrenaline narrows blood vessels
Unlike adrenaline increases both systolic and diastolic blood pressure without affecting the pulse pressure.
Adrenaline increases the oxygen consumption of the tissues, increases the basal metabolic rate, increases the heat in the body, increasing body temperature.Blood Sugar influenced adrenalin increases due to the decay of glycogen in muscle and liver.This process is performed by stimulating the formation of cyclic adenizinomo adrenaline-nofosfata, which occurs in the presence of phosphorylase activation that promotes the disintegration of glycogen in liver and muscles.The flow of these processes ensures the supply of energy, which are carried out by a variety of metabolic changes -.. Heat production, the active transport of ions, etc.
Norepinephrine has on the metabolism significantly less effect than adrenaline.
Epinephrine and norepinephrine exert a lipolytic action, increasing yield neesterofitsirovannyh fatty acids from adipose tissue and stimulate fat oxidation.
catecholamines contribute to the transition of potassium out of the cell into the extracellular fluid.
Adrenaline reduces the tone of the muscles of the bronchi, gall bladder, uterus, skin tone and peristalsis, causes contraction of the sphincter.The action of noradrenaline in this respect is much weaker than that of adrenaline.
adrenaline and to a lesser extent norepinephrine cause eosinopenia and increase in the number of neutrophils in the peripheral blood.Adrenaline increases the excitability of the cerebral cortex.He played an important role in maintaining the activity of the reticular formation, and it has a stimulating effect on the hypothalamic centers.In high doses, the adrenaline inhibits the transmission of the case to preganglionarnah postganglionic fibers in the sympathetic ganglia.
externally entered norepinephrine does not render exciting action on the central nervous system.However, the concentration of noradrenaline hypothalamic centers is high, which indicates its importance in activity centers localized in this area.As mentioned above, norepinephrine is the main mediator of ensuring the transfer of excitation in the sympathetic ganglia.
Experimental studies have shown that adrenaline stimulates the production of ACTH by the anterior pituitary.However, while adrenalin rise above the physiological level of ACTH increases the production of, apparently, it plays a secondary role in the regulation of pituitary function adrenocorticotropic.
- Physiology of the adrenal cortex
- Cushing syndrome - Cushing
- diagnosis and course of the syndrome Cushing's
- Treatment syndrome Cushing's
- androgen-producing tumors of the adrenal cortex
- Primary aldosteronism (syndrome Conn)
- Clinical evaluation of laboratory studies of the functional state of the adrenal cortex
- feminizing tumor of the adrenal cortex
- Diseases of the adrenal medulla
- Treatment of chronic adrenal insufficiency
- congenital (inborn) hyperaldosteronism
- congenital virilizing adrenal hyperplasia
- Treatment of congenitaladrenal hyperplasia
- Acute failure of the adrenal cortex
data on the effect of catecholamines thyroid contradictory.There are observations that indicate that catecholamines reduce the accumulation of radioiodine by the thyroid gland.On the other hand, saw an increase in capture of radioactive iodine by the thyroid gland under the influence of adrenaline, and on the other hand does not capture changes noted radioiodine under the influence of catecholamines.Isolation of iodine by the thyroid gland associated with proteins, under the influence of adrenaline rises.There are observations that indicate increased secretion of thyroid-stimulating hormone under the influence of adrenaline, as well as a possible increase in the sensitivity to the thyroid stimulating hormone.
By raising the blood sugar level, adrenaline stimulates the production of insulin by beta cells of the pancreatic islets.
There is evidence that the adrenaline inhibits the function of sexual glands.
sympathoadrenal the whole system plays an important role in the adaptation of an organism to a changing environment.