[Status of vasopressin-, oxytocin- and corticoliberin-synthesizing structures of the hypothalamus in experimental diabetes mellitus in rats of different sexes].

The endocrine status of the pancreas and the hypothalamic neurosecretory nuclei were studied by radioimmunoassay, immunocytochemical, morphometric and histochemical methods in Wistar rats of both sexes with experimental diabetes mellitus. The development of diabetes mellitus was characterized by beta-cell destruction and insulin concentrations reduction in these cells and the blood, by increase of glucagon and somatostatin levels in the alpha- and delta-cells, respectively, as well as by the growth of these substances concentrations in the peripheral blood. These changes were parallelled by activation of the vasopressin-, oxytocin and corticoliberin-synthesizing neurones of the paraventricular and supraoptic nuclei of the hypothalamus, as evidenced by morphometric findings and by increase of the blood vasopressin and corticoliberin concentrations and oxytocin level in the hypothalamus. Experimental diabetes mellitus was found to be characterized by activation of the hypothalamo-hypophyseo-adrenal system. Functional differences in the contribution of vasopressin- and oxytocin-synthesizing neurones of the hypothalamic nuclei in the pathogenesis of the disease is shown, as are their sex-specific reactions.