Reproductive state modulates ethanol intake in rats: effects of ovariectomy, ethanol concentration, estrous cycle and pregnancy.

Intact adult female rats had a greater preference for a 4% (v/v) ethanol solution than ovariectomized (OVX) rats in a two-tube preference situation. This preference difference was not particular to the 4% concentration, but was exhibited for solutions ranging from 1-9% ethanol. OVX animals reached peak preference at weaker ethanol concentrations than did control animals, while the volume of absolute ethanol consumed by each group was high dependent on the concentration of ethanol offered. OVX, but not intact, rats showed a strong positive correlation between alcohol preference and preference for a saccharine solution. Pregnant and lactating rats exhibited depressed preference for 4% ethanol. Preference returned to control levels following weaning. Ethanol intake and preference varied systematically over the four-day estrous cycle, being lowest on the day of proestrus.