[Morphofunctional state of the rat supraoptico-neurohypophyseal system in hypoparathyroisis].

Volumes of nuclei and nucleoli of neurosecretory cells of the hypothalamic supraoptic nucleus were investigated morphometrically, and the amount of neurosecretion in the posterior hypophyseal lobe was determined photometrically in rats at varying time of parathyroprivic hypocalcemia. The data obtained were indicative of increased function of the hypothalamic supraoptic nucleus on the 5th day of parathyroprivic hypocalcemia and a decrease in the amount of neurosecretion in the posterior hypophyseal lobe that can be interpreted as a sign of an increased discharge of neurosecretion into the blood flow. A decrease in function of neurosecretory cells of the supraoptic nucleus in parallel with an increase in the amount of neurosecretion in the posterior hypophyseal lobe on days 15 and 30 of development of parathyroprivic hypocalcemia indicated retention of a discharge of neurosecretion. Return of neurosecretion to normal tended to occur on day 60.