title: Fate of tritium derived from prenatally administered tritiated methadone in dams and neonatal rats.
abstract: Tritiated methadone (3HME) was administered to gravid rats on the last week of gestation, fostered neonates periodically sacrificed, and brain and liver tritium determined by combustion. Concentrations of tritium were highest in brain on the day of birth and declined rapidly so that after 5 days, 20% remained, and after 25 days, 2% remained; similar values were found in liver. In maternal brain, concentrations on the day of birth were essentially the same as offspring brain. The brain concentrations of methadone are discussed in relation to neurobehavioral effects.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D005260:Female; D008099:Liver / Q000378:metabolism*; D008431:Maternal-Fetal Exchange; D008691:Methadone / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats
chemical_list: D008691:Methadone