[The vasopressin-, oxytocin- and corticoliberin-synthesizing structures of the hypothalamus in rats with diabetes mellitus under hypoxic exposures].

Hypothalamic mechanisms of neurohormone regulation of endocrine pancreas in diabetes mellitus, adaptation to hypoxia and their combination were studied on Wistar rats. To evaluate the condition of supraoptic nucleus (SON) secretory function, paraventricular subnuclei (PVH) of hypothalamus and endocrine pancreas, we used radioimmunoassay, immunocytochemical, morphometrical and histochemical methods. Hyperglycemia, hypoinsulinemia, glucagon and somatostatin synthesis and secretion intensification in diabetes mellitus is accompanied by marked reorganization of hypothalamic neurohormones (CRF, vasopressin, oxytocin) secretion with corresponding signs of activity increase of synthesizing their hypothalamus nuclei and subnuclei and also ACTH, corticosterone, cortisol rise in blood. Adaptation to hypoxia caused hypoglycemia, activated insulin biosynthesis, changed glucagon and somatostatin synthesis and secretion. CRF concentration, corticosterone and cortisol, ACTH in blood was not changed, vasopressin concentration lowered, oxytocin in median eminence of hypothalamus increased to a higher degree than in diabetes. Adaptation to hypoxia corrected impaired hormone balance and state of Langerhans islets (beta-cells destruction process inhibition, insulin biosynthesis stimulation, glucagon and somatostatin secretion decrease) in diabetes mellitus, hypothalamic neurohormones participating in this process.