Sex differences in osmotic stimulation of vasopressin release in rats chronically exposed to alcohol

Abstract

Whether the purported differences in alcohol effects in males and females may be due to alcohol influence on estradiol and progesterone mediation of vasopressin (VP) release was studied in Sprague-Dawley male and female rats exposed to control, moderate alcohol (1.2% ethanol) or high alcohol (6.4-6.7% ethanol) liquid diet for 4-6 weeks. VP response to an osmotic stimulus (5% NaCl i.v. infusion) and pituitary VP stores in relationship to circulating VP were examined. In males, alcohol did not appear to affect VP osmotic stimulation. In females, however, alcohol affected VP osmotic stimulation sensitivity depending on estrous cycle phase, and appeared to alter circulating estradiol and progesterone relationships with VP stores and release. Results thus indicate that females may be more susceptible to alcoholinduced changes in VP regulation of water balance.