[³H]naloxone binding in the brains of young rats perinatally exposed to methadone

Levorphanol-sensitive [³H]naloxone binding was measured in the spinal cord and various brain regions of 21-day old rat offspring maternally exposed to 5 mg/kg dl-methadone hydrochloride during gestation and/or lactation. With only a few exceptions, perinatal methadone exposure did not have a profound effect on opiate receptor binding. No obvious relationship between the neurobiological disturbances reported earlier in rats maternally exposed to methadone and changes in opiate receptor populations could be ascertained in this study.