Karnaukh M. Morpho-functional status of enkephalinergic system of the hypothalamus in experimental diabetes mellitus.

The thesis for the degree of candidate of medical sciences, specialty 14.03.04 - pathological physiology. - Zhaporizhzhya State Medical University, Ministry of Health of Ukraine, Zhaporizhzhya, 2015. The dissertation is devoted to studying the role of enkephalinergic system of the hypothalamus in rats in mechanisms of experimental streptozotocin-induced diabetes. Based on a comprehensive study of the hypothalamus in rats with prior colchicine injection using the modern morphometric, densitometric and immunofluorescence methods the morphofunctional state features of met-enkephalinergic and leu-enkephalinergic systems of hypothalamus in normal conditions and with experimental streptozotocin-induced diabetes mellitus in rats were established. For the first time it was shown that the development of diabetes is accompanied by a gradual activation of the biosynthesis of met-enkephalin in parvocellular neurosecretory subnuclei of paraventricular and arcuate nuclei, and also in the magnocellular neurons of supraoptic nucleus with an increase in their total content of neuropeptides. However, in neurons of posterior magnocellular subnucleus of paraventricular nucleus the synthesis of met-enkephalin in the initial stage of diabetes significantly suppressed and only subsequently its renewal and intensification will be determined. For the first time it was found that the development of experimental diabetes leads to increased expression of leu-enkephalin in the hypothalamus, which is characterized by significant growth in the number of immunopositive neurons both in magnocellular and in parvocellular neurosecretory structures, as well as in so-called "non-secretory" nuclei of the hypothalamus. It was proved that the development of diabetes reduced the intensity of neurosecretion almost in all structures of the hypothalamus, except the magnocellular neurons of the supraoptic nucleus, which should be seen as a manifestation of dysregulative pathology in diabetes. Keywords: hypothalamus, met-enkephalin, leu-enkephalin, diabetes mellitus.