AGE MORPHOLOGY OF THE MEDIAN EMINENCE OF NEUROHYPOPHYSIS IN EXPERIMENTAL DIABETES MELLITUS (ULTRASTRUCTURAL STUDIES)

The volume fraction of neurosecretory granules in the nerve fibers of the outer layer of the median eminence of neurohypophysis was increased (p <0.05) in 3- month-old animals on day 7 of streptozotocin-induced diabetes. The amplification of fenestrae in portal blood capillaries and extension of pericapillary spaces were observed while the morphology of the median eminence of neurohypophysis in 24- month old animals remained intact. The functional activity of neurosecretory cells of the anterior and medial hypothalamus in tested animals enhanced on experimental day 28 as was evidenced by increased volume fraction of neurosecretory granules in external (p <0.01) and internal (p <0.01) layers of the median eminence. Development of diabetic microangiopathy was revealed in portal blood capillaries.