Rat accessory sex glands response to oxytocin under different light regimens

Effects of oxytocin (0.25 IU OT/100 g/d for 3 days) on accessory sex glands structure and catecholamine content were examined in rats kept on two different light regimens. In 12 h light/12 h dark conditions ventral prostate responded to OT by a regression of the epithelial component and an increase in dopamine content. Coagulating gland structure was not affected, but noradrenaline content of the seminal vesicle+coagulating gland complex was enhanced. Constant lighting per se caused atrophic changes in the prostatic epithelium, evident by decreased total volume and by increased percentage of acini containing cuboidal epithelium. OT treatment considerably prevented the epithelial atrophy without affecting catecholamines level. In the seminal vesicle+coagulating gland complex it reduced the dopamine content. Since this light regimen elevated the plasma ACTH, the altered accessory sex gland response to OT seems to be due to the stress-induced changes in the neuro-endocrine factors conditioning their function. The effects of OT on accessory glands catecholamine content indicate interferences with their autonomic control.