No abstract

Ventral prostate response to oxytocin (OT) was examined in intact and castrated adult rats. The treatment consisted of 10 daily subcutaneous injections of 0.25 IU OT per 100 g body weight, which for orchiectomized rats began immediately after surgery. OT induced prostatic response only in castrated animals. Stereologic analysis revealed changes in the epithelial component, its total volume and surface being increased. The acinar lumen as well as the glandular weight were also enhanced. A possibility that the ventral prostate is the target organ for OT is discussed.

The development and regeneration of the adrenal glands were examined by stereological and morphological methods in 20-day-old fetal, as well as 3-day- and 14-day-old neonatal male rats born to dams treated with dexamethasone (Dx) on day 16 of gestation. In the fetuses and 3-day-old rats, zona fasciculata (ZF) and zona reticularis (ZR) were analyzed as one inner zone (IZ), while in 14-day-old animals they were analyzed separately. Single Dx treatment (1.5 mg/kg b.w.) of the dams led to atrophic changes in the adrenal cortex of the fetuses. These changes were visible to a certain degree up to the 14th neonatal day. Administration of Dx to pregnant rats induced a significant decrease of both adrenal weight and volume, as well as the volume of zona glomerulosa + capsule (ZG + C) and IZ, both in fetuses and 3-day-old rats. This was due to a decrease in the number but not the volume of cortical cells. Also, necrotic cortical cells, infiltrations and resorption zones accompanied by the presence of macrophages, giant cells and lymphocytes were observed. In 14-day-old animals, the degree of atrophic changes in the adrenal cortex was reduced. Changes were observed only in ZR which was decreased in volume resulting from both a significant decrease of the volume and number of cortical cells. Then number of macrophages was somewhat increased, while giant cells were not present. However, the total number of parenchyma cells in ZG was increased, pointing to the possibility of renewal of cortical cells within this zone. The results of the present study demonstrate that even a single Dx dose given to pregnant rat during the period critical for the development of the hypothalamo-pituitary-adrenal system in the fetuses leads to marked changes in the structure and function of the fetal adrenal glands which are partially maintained up to the 14th day of postnatal life.

No abstract

Effects of oxytocin (OT) on the adrenal chromaffin tissue of male rats were examined by coupled morphometric and biochemical techniques. Synthetic OT was administered in doses of 0.14 and 0.25 IU/100 g/d during 7 or 10 consecutive days and the effects were followed 1, 24, 72 and 168 hours after the last injection. The function and structure of chromaffin cells were affected by the higher dose of OT only. They caused divergent responses on their amine contents. Adrenaline, noradrenaline and dopamine contents were increased, while serotonin content was decreased. These changes were different in duration and time of incidence. Stereological analysis showed an enhanced number of chromaffin cells and an increase in their total volume. The parallelism between the changes in chromaffin cell number and the catecholamine content strongly suggests a mitogenic effect of the applied OT.