The effects of chronic postweaning amphetamine on rats exposed to alcohol in utero: Weight gain and behavior

Offspring of rats fed alcohol, pair-fed, or fed ad lib control diets during pregnancy were administered a dose of amphetamine (0, 2 or 10 mg/kg) daily from postnatal day 22 (PN22) to PN42. Body weight was measured regularly from PN22 to PN60, and behavior was measured on PN22, PN28, PN36 and PN42. Rats exposed to alcohol in utero weighed less than controls at birth and throughout most of the experiment, despite a significantly accelerated weight gain relative to controls. By PN60, prenatal alcohol-exposed rats weighed the same as pair-fed controls. There were dose-dependent reductions in the rate of weight gain during amphetamine administration. After the daily injections stopped, the high-dose (10-mg/kg) amphetamine groups showed a higher growth rate than the 0-mg/kg and 2-mg/kg groups. There were no interactions between prenatal treatment and dose of amphetamine on body weight gain. Rats exposed to alcohol in utero showed a greater locomotor activation than controls given 2 mg/kg amphetamine. The magnitude of the locomotor activation to this dose of amphetamine decreased equivalently over the four test days for all prenatal treatment groups. Male but not female rats exposed prenatally to alcohol showed an apparent sensitization to 10 mg/kg amphetamine not seen in control rats between PN28 and PN42. There were no group differences in amphetamine-induced stereotypy or SCH-23390-induced catalepsy. The results implied that children with Fetal Alcohol Syndrome who may be treated for attentional dysfunction would show different dose-responses for some behavioral effects of CNS stimulants, but not for growth-retarding “side effects.”