Secretory

Secretory, or chromaffin, granules in which these catecholamins in cells of two different types are postponed, also find out differences on rate of a sedimentation in a density gradient. It is not known, than this difference between granules as they order ultram tramadol contain the same fibers and is caused. Catecholamins are postponed in granules in the form of a complex. Chromogranin consisting of fiber And, enzyme Dofaminum-beta-oksidazy and a considerable quantity nucleotides, mainly , present at stoichiometric quantities in relation to catecholamins. Though processes of formation of chromaffin granules are deciphered short, some experimental data testify to existence of a following number of events. Consider, that like granules of others cells of a granule of a chromaffin tissue are formed in a lamellar complex and at the first stages contain chromogranin And, Dofaminum-beta-gidroksilazu and other fibers synthesised in and transferred to a lamellar complex. Then, in process of maturing of granules, in them activly are transported and concentrate and Dofaminum. Believe, that acidic will neutralise the basic amines and by that provides possibility of their more effective accumulation in to the form. Besides, provides with energy transport processes and, possibly, also it is utilised at stimulation of production of catecholamins. SECRETION Liberation of secretory products of chromaffin cells occurs by an exocytosis. Elektronno-microscopic researches have allowed to find out various morphological stages of this process ( 3-16). The liberation mechanism includes merge of a membrane of granules to a plasmatic membrane and splitting of the merged membranes.
Thereof contents of granules are liberated immediately in extracellular space without the previous contact to a cell cytoplasma. The granule membrane, having released from the contents, is involved in a cell by an invagination and endocytosis and blasted by enzymes after phagocytosis by lysosomes. Immediate physiological stimulus for liberation of catecholamins is Acetylcholinum. Stimulation by the electric category of the cholinergic preganglionic celiac. A nerve going to an adrenal, leads to fast emission of contents of chromaffin granules. Acetylcholinum allocated from the preganglionic terminations of a nerve, operates, apparently, on buy vpxl now online an external surface of a chromaffin cell with the help yet not found out mechanism. Acetylcholinum does not cause liberation of catecholamins from the isolated chromaffin granules. Important influence on synthesis of catecholamins is rendered also by glucocorticoids. These substances and , operating by stimulation of liberation of glucocorticoids, raise activity of the enzymes which are taking part in synthesis of catecholamins. The hypophysectomy leads to appreciable depression of activity of these enzymes which can be restored introduction or glucocorticoids. Glucocorticoids, apparently, immediately modulate level of enzyme of a feniletanolamin-N-methyltransferase and by that quantity of the adrenaline produced by a cerebral layer of adrenals. However level and Dofaminum - | 3-gidroksilazy in a larger measure depends on the maintenance in blood , than glucocorticoids. It allows to assume, that in rising of activity of the specified enzymes somehow can participate , formed at action on a cortex of adrenals. Close mutual relations of metabolic processes in cortical and cerebral layers of an adrenal are justified by the general reactions of these two endocrine tissues to physical stresses. The stress is accompanied by rising of secretion and glucocorticoids, that in turn promotes adrenaline production a cerebral layer of adrenals. Thus, the cerebral layer of adrenals can be surveyed as one of many organs-targets of products of a cortex of adrenals in which changes develop at stress. It is more than that, the close affinity of a cortex and a cerebral layer of adrenals, and also that fact, that venous outflow from a cortical layer passes through cerebral, frame anatomic possibility of hit in last high concentration of glucocorticoids before they will undergo to delution in the general circulation. SELECTIVE LIBERATION Some stimulus selectively raise allocation from a cerebral layer of adrenals or adrenaline, or Noradrenalinum. Apparently, it is caused by selective stimulation of this or that type of cells of a cerebral layer [36]. The hypoglycaemia or nicotine selectively stimulates secretion of adrenaline and causes corresponding attrition of medullary stocks of adrenaline whereas the carotid occlusion leads to occurrence of the adrenal secret containing of few adrenaline in relation to Noradrenalinum. Selective secretion of separate catecholamins quite could concern a functional role of this or that of them as biological activity of these hormones is characterised by essential differences. Noradrenalinum, for example, causes narrowing of vessels whereas adrenaline causes their expansion in sceletal muscles and possesses more expressed metabolic action. Research of influences of emotional stress on secretion of catecholamins also testifies to the differentiated reaction. As a rule, the passive, intense, uneasy behaviour is accompanied by rising of secretion of adrenaline, and aggressive, hostile reactions are accompanied by primary intensifying of secretion of Noradrenalinum.