title: The effect of prenatal procarbazine treatment on brain development in the rat.
abstract: Groups of pregnant Sprague-Dawley rats were treated orally with procarbazine, an antineoplastic drug, at dose levels of 0, 1.0, 2.5, 5.0, 7.5, and 10.0 mg/kg/day from days 12 through 15 of gestation. Following normal delivery, offspring were raised until day 21 and sacrificed, and their brains removed and weighed. A dose-dependent micrencephaly, characterized by hypoplasia of the cerebral hemispheres, was seen starting at 2.5 mg/kg/day. In a second study, groups of pregnant female rats were given a single dose of 10 mg/kg procarbazine on gestation day 12, 13, 14, or 15. Micrencephaly occurred in 21-day-old offspring from all groups, with the greatest effect induced on days 13, 14 and 15. Analysis of brain region weights revealed a maximum reduction in neocortex weight in offspring from groups treated on days 13 and 14. The hippocampus, cerebellum, and diencephalon-midbrain were also reduced in size, depending on the day of treatment, while the corpus striatum and pons-medulla were spared. In a final study, embryos from females treated on gestation days 12 through 15 were removed, fixed, and sectioned at 24-hour intervals starting on gestation days 13. Necrosis and cellular degeneration were observed with decreasing severity in the telencephalon, diencephalon, mesencephalon, and medulla. The neocortex of 20-day treated fetuses was characterized by a thickening of the ventricular zone and reduced cellularity of the cortical plate.
mesh_terms: D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000254:growth & development* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D005260:Female; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D011344:Procarbazine / Q000633:toxicity*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D011344:Procarbazine