Morpho-Functional Characteristics of Neurosecretory Cells from Preoptic Nucleus of the Brown Frog Rana temporaria after Hypophysectomy and Vasotocin Administration

摘要

Vasotocin-positive cells from preoptic nucleus of frog Rana temporaria L. were studied morphometrically in intact and hypophysectomized individuals (in 10 days after adenohypophysectomy) in control and after intramuscular injections of arginine-vasotocin (VT) in the dose of 50 ng per 10 g weight. A statistically significant increase of nucleolar volume of vasotocin-positive cells in intact and particularly in hypophysectomized frogs was revealed after vasotocin administration. This was accompanied by a decrease of the number of vasotocin-poor cells and an increase of the number of cells storing vasotocin in intact frogs, while the inverse was true for hypophysectomized animals. The results obtained indicate that in the absence of adenopituitary hormones in forges, a positive direct feedback is revealed between the blood level of vasotocin and intensity of its synthesis in and release from neurosecretory cells of preoptic nucleus.