Fetal and infant rats were maternally exposed to morphine sulfate during gestation and lactation. Drug was administered twice daily by i.p. injection, with dosages gradually increased from 10 mg/kg/injection to a maintenance level of 40 mg/kg/injection. Offspring observed during the preweaning period had a reduction in body, brain and cerebellar weights, as well as in brain length and cerebral and cerebellar widths. Deficits persisted in young rats observed 5 1/2 weeks after cessation of drug exposure and in animals continuing to receive twice daily i.p. injections of 20 mg/kg/injection. These results indicate that maternal morphine treatment retards the growth of young rats and impairs brain development.
All Science Journal Classification (ASJC) codes