Pharmacokinetics of ethanol in the guinea pig.

Chronic consumption of ethanol by pregnant and nonpregnant guinea pigs for 8 weeks at doses of 1.2 or 1.6 g/kg body weight twice daily affected pregnancy outcome and changed the pharmacokinetics of ethanol elimination. Ethanol treatment as compared to that of isocaloric sucrose decreased maternal weight, and decreased both the litter size and the number of liveborn offspring. Total litter weight was significantly decreased with the low ethanol dose (12% alcohol-derived energy). During pregnancy, low and high doses produced peak blood ethanol concentrations (BEC) of 89 +/- 8 mg/dl (mean +/- SE) and 125 +/- 6 mg/dl, respectively. At the high dose, peak BEC decreased dramatically (about 30%) in both pregnant and nonpregnant animals from treatment weeks 0 to 4; thereafter peak BEC remained depressed up to 8 weeks of treatment, which occurred with a concomitant increased volume of ethanol distribution. With both doses, rates of ethanol elimination and Michaelis-Menten's Vm values were significantly lower among pregnant as compared with nonpregnant guinea pigs during 8 weeks of treatment. These data suggest that the guinea pigs can be a valuable animal model to study the effects of low ethanol doses on fetal growth, the adaptation of peak BEC with duration of treatment and the lower rate of ethanol elimination in pregnancy.