title: A teratogenicity study on hydroxyurea and diphenylhydantoin in cats.
abstract: Hydroxyurea, an antitumor drug and known teratogen in rat, miniature swine and dog, and diphenylhydantoin, a teratogen in mouse and rat, were assessed for teratogenic effects in cat. Pregnancies were induced, by synchronizing gonadotropin-stimulated estrus and ovulation with natural copulations. Hydroxyurea at 50 or 100 mg/kg, and sodium diphenylhydantoin at 1 or 2 mg/kg dosages, were administered orally in single daily doses from gestation days 10-22. Appropriate controls given empty capsules, were included for each drug. Cats were necropsied on gestation day 43. Fetuses were examined for external, visceral and skeletal malformations. Hydroxyurea at 50 mg/kg dose produced a low teratogenic activity and at 100 mg/kg a high incidence of non-pregnancy and resorptions with, consequently, fewer live fetuses. Diphenylhydantoin gave no clear evidence of teratogenicity at any test dose but was embryolethal at the maternally toxic dose of 2 mg/kg. So far, studies conducted suggest that the cat is a useful species for screening drugs and chemicals for their teratogenic potential.
mesh_terms: D000014:Abnormalities, Drug-Induced; D000818:Animals; D002415:Cats / Q000196:embryology*; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D005260:Female; D006918:Hydroxyurea / Q000633:toxicity*; D010672:Phenytoin / Q000633:toxicity*; D011247:Pregnancy; D013045:Species Specificity; D013997:Time Factors
chemical_list: D010672:Phenytoin; D006918:Hydroxyurea