Acher and . [9] these for the first

Acher and . [9] these for the first time have separated from active hormones more 20 years ago. However only recently it was possible to receive separate in pure enough kind to define them properties [10]. At the person and the majority of mammals immunologically and are allocated two basic types. One of them is exclusively in the granules containing Oxytocinum, and the second - only in the granules containing a vasopressin. Both represent, apparently, one-chained polypeptides with initial molecular mass approximately 10000, but depo medrol in strong solutions easily form and . each type equally well binds Oxytocinum and a vasopressin. It testifies that specific communications with the hormones, found out in vivo, are caused anatomic . The optimum for linkage of hormones with makes 5, 2-5, 8. And K-approximately 2-105. Such parametres provide full dissociation of a complex - a hormone in plasma. The amino-acid sequence of a number is partially defined, and taped appreciable internal that part of a molecule as which consider as a place of linkage of hormones. BIOSYNTHESIS AND SECRETION The vasopressin and Oxytocinum are synthesised in cellular bodies and kernels, packed into granules with corresponding and transported on axons to their final expansions where are stored before the liberation [2, 11]. Though each hormone is produced by special population of neurones [12], mechanisms of that biosynthesis and another, apparently, are identical. Including of amino acids in a vasopressin demands participation of ribosomes and passes, possibly, through-stage synthesis of the macromolecular precursor or a prohormone which in the course of transport is split with formation active [11].
Synthesis of hormones as mechanically, and is anatomically closely bound, apparently, to synthesis corresponding . So, rats of line Brattleboro with hereditary absence of ability to synthesis of a vasopressin are deprived also corresponding [12]. And on the contrary, many malignant tumours which in the course of dedifferentiation get ability to vasopressin and-or Oxytocinum synthesis, contain and corresponding [13]. Rate of synthesis of hormones is enlarged under the influence of the stimulus strengthening their secretion, such, as a dehydration. However at least at rats this compensatory reaction develops only gradually and is often expressed not in that degree completely to compensate the raised rate of secretion. Vasopressin stocks in a neurohypophysis at chronic stimulation of its secretion that is observed in the conditions of long abstention from drink, are usually sharply exhausted. Process of packing of a hormone with the in granules and their transport on an axon is found out not completely. Granules are surrounded by a membrane and at some kinds of animals are formed, apparently, of a lamellar complex in a perikaryon. Transport can be carried out by means of a special phenomenon of the axonal current observed in other nervous structures, or any faster mechanism with participation of microtubules. buy phentrimine Secretion of a hormone and bound to it is carried out, obviously, by means of process of the exocytosis similar described for other neurosecretory systems [14] dependent on calcium. According to this point of view, process "is started" by diffusion on a neurone of electric impulse which causes a cellular membrane, calcium inflow, merge of secretory granules to a membrane and pushing out of their contents. SECRETION REGULATION It is known, that vasopressin secretion is influenced by many factors [15-17]. Most important of them in physiological conditions is, possibly, osmotic pressure of liquid mediums of an organism. Influence of this factor on vasopressin secretion is mediated by an osmoreceptor located in a forward hypothalamus close, but separately from and , kernels [18] ( 9-1 see). Functional properties of an osmoreceptor remind those of a discrete or "adjusting" receptor ( 9-3). When the plasma osmolality is kept below a certain minimum or threshold size, the vasopressin maintenance constantly is in it at the minimum or indefinable level. If the osmolality exceeds this threshold vasopressin level in plasma abruptly raises in direct ratio its osmolalities. An inclination of the line reflecting The osmoregulation system is capable to react not only is sensitive, but also is rather exact [18]. At inspection of some adult persons in carefully controllable conditions of position of a body and physical activity vasopressin level in plasma and its osmolality almost always find out close correlation. Rather wide disorder which characterises dependence between vasopressin level in plasma and its osmolality in population of healthy adult persons (see, 9-3), is caused basically by specific features of adjustment and sensitivity of system.