title: Embryotoxicity of the folate antagonist methotrexate in rats and rabbits.
abstract: The prenatal effects of methotrexate (MTX) in rats and rabbits were assessed. It was found highly embryotoxic in postimplantation rat embryos; 0.3 mg/kg ip or less caused nearly total embryolethality with slight teratogenicity. Rabbit embryos were far more resistant to small doses of MTX than rats, but 19.2 mg/kg iv, when given during days 10 to 15 of gestation, produced little death and a constant spectrum of malformation in a high percentage of offspring. Cleft palate, skull defects, and severe fore- and hindlimb dysplasias, occurred with a high degree of regularity and were strongly dose and developmental-stage specific.
mesh_terms: D000014:Abnormalities, Drug-Induced; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D005313:Fetal Death / Q000139:chemically induced*; D005327:Fetal Resorption / Q000139:chemically induced; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D008727:Methotrexate / Q000008:administration & dosage / Q000633:toxicity*; D011247:Pregnancy; D011817:Rabbits; D051381:Rats; D013045:Species Specificity
chemical_list: D008727:Methotrexate