Daily hypoxia (6 h, 6000 m) changed the functional state of endocrine pancrease of male and female Wistar rats. The actions of hypoxia on functional state of supraoptic (SO) and paraventricular (PV) nuclei of hypothalamus and islet cells of endocrine pancreas were examined using immunocytochemical, histochemical, morphometric and radioimmunoassay methods. Increase of insulin biosynthesis in beta cells and glucagon secretion of alpha cells, and decrease of the somatostatin contents in delta cells of pancrease islets have been investigated. The functional activity of vasopressinergic magnocellular subnucleus of PV increased, but that of SO decreased with reduction of vasopressin blood concentration at the same time. The functional state of oxytocin synthesis subdivisions of PV and SO were sex dependent, but the oxytocin contents in median eminence increased.