title: Effect of chronic maternal methadone exposure on perinatal development.
abstract: The effect of perinatal exposure to methadone on body growth and brain development was studied in rat. Female Sprague-Dawley albino rats received daily intraperitoneal injections of 5 mg/kg dl-methadone-HCl during gestation and lactation. Body weights were reduced in drug-treated mothers during gestation and the first 2 weeks of lactation. No differences in gestation time, litter size, or infant mortality were recorded, however methadone-treated offspring grew more slowly than controls. Weight deficits persisted in rats observed 5-1/2 weeks after cessationof drug exposure (group 1) and in animals continuing to receive daily interperitoneal injections of 5 mg/kg (group 2). From birth to day 21, brain weight and length, cerebral width and cerebellar weight and width were generally smaller in methadone-exposed rats. Brain measurements of group 1 and group 2 animals on day 60 revealed a reduction in brain and cerebellar weights and cerebral and cerebellar widths from control values. Brain:body weight and cerebellum:brain weight ratios were similar to controls. Analysis of these results indicates that maternal methadone treatment retards the growth of young rats and affects brain development.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development*; D001835:Body Weight / Q000187:drug effects*; D001921:Brain / Q000187:drug effects* / Q000196:embryology / Q000254:growth & development; D002531:Cerebellum / Q000187:drug effects / Q000196:embryology / Q000254:growth & development; D005260:Female; D005333:Fetus / Q000187:drug effects*; D008297:Male; D008431:Maternal-Fetal Exchange; D008691:Methadone / Q000633:toxicity*; D009929:Organ Size / Q000187:drug effects; D011247:Pregnancy; D051381:Rats
chemical_list: D008691:Methadone