The study was performed in 80 albino Wistar rats of both sexes. Pancreatic A-, B- and D-cells state were studied by means of indirect immunofluorescence, using monoclonal antibodies to insulin and anti-serine to glucagon and somatostatin. This method reflects state of endocrine cells secretory activity most adequately and is an optimal one for studying the structure, function and qualitative determination of hormones. Peculiarities of A-, B- and D-cells relationship in diabetes, adaptation to hypoxia and their combinations taking animals sex into account were demonstrated. This is, first of all, an inverse dependence between insulin content on one hand and between glucagon and somatostatin on the other. It is also a greater vulnerability of big islets in diabetes. Besides, positive effect of adaptation to hypoxic hypoxia on the course of the experimental diabetes was demonstrated, which may be expressed in several ways: by insulin biosynthesis stimulation and new B-cells appearance, by normalization of glucagon secretion by A-cells and their reaction to hyperglycemia, depending on insulin and somatostatin content in D-cells and by inhibition of destructive process in B-cells.