THE EFFECTS OF COCAINE EXPOSURE PRIOR TO AND DURING PREGNANCY IN RATSFED LOW OR ADEQUATE PROTEIN DIETS

Sprague-Dawley rats were fed a diet of low protein content (6% casein) , an isocaloric diet of adequate protein content (25% casein), or a la boratory chow diet for 5 weeks prior to mating and throughout pregnanc y. Within each diet group, rats received either cocaine (30 mg/kg IP t wo times per week prior to mating and 30 mg/kg or 40 mg/kg SC daily fr om days 3 to 18 of pregnancy) or saline injections. Cocaine produced a greater reduction in food intake during pregnancy in the malnourished group compared with the other two diet groups. The effect of cocaine on food intake was minimal in chow-fed rats. Weight gain in pregnancy was reduced by cocaine in a dose-dependent manner, and by malnutrition . Both prenatal cocaine and malnutrition impaired skeletal maturation of the pups, but there was no additive effect of the two insults on th is measure. Litter size was significantly reduced by the 40 mg/kg, but not by the 30 mg/kg dose of cocaine across all diet groups. Consequen tly, the 40 mg/kg dose of cocaine proved to be fetotoxic in this model . Birth weight was significantly reduced by prenatal malnutrition but not by prenatal cocaine. Gestation length was unaffected by either ins ult. Hence, the ability to detect a diet x drug interaction was depend ent upon the variable being measured.