The effect of X-radiation on the hypothalamo-hypophyseal neurosecretory system of the rat.

The aim of the study was to reveal alterations in the macrocellular neurosecretory system of the rat which occur under the influence of X-radiation. The experiment was carried out on 15 male Wistar rats, divided into 1 control and 4 experimental groups. The animals were subjected to total-body-X-irradiation in a dose of 300R. Brains and cerebral pituitaries were collected after decapitation and fixed in Bouine's fluid. Staining with haematoxylin & eosin and paraldehyde fuchsin was applied. A reduction in the neurosecrete content was found after 7 days following irradiation both in the area of perikarya and nerve processes of SON and PVN. In animals dissected on the 14th and 21st day following irradiation, a shift of neurosecrete along the neurosecretory path was observed (via nerve processes to the posterior lobe of cerebral pituitary). On the 28th day, the morphological picture of the system examined was similar to the control one. The above results indicate that initially X-radiation causes a decrease in the production of neurosecrete within SON and PVN; later, however, the amount of neurosecrete is increased, like in control nuclei.