title: Abnormal development of mouse embryos exposed to methylnitrosourea before implantation.
abstract: On day 2 of gestation mice were exposed to single i.p. injections of 5, 10, 20, and 40 mg/kg methylnitrosourea (MNU). Evaluation at term revealed 100% embryolethality in the 40 mg/kg group but no signs of maternal toxicity (LD50 = 400 mg/kg). In mice treated with 5 and 10 mg/kg, no malformations could be detected at term. In contrast, 40% of the live fetuses exposed to 20 mg/kg MNU showed developmental abnormalities of vertebrae, ribs, long bones, and kidneys. Analysis of postnatal development 3 weeks after birth indicated a significant increase in mortality in the offspring of all animals exposed to MNU on day 2 of pregnancy. Further developmental or morphologic anomalies could not be detected in the offspring up to the age of 6 months, when autopsy was performed. The data show that exposure to MNU before implantation has embryolethal and teratogenic effects in a dose range one order of magnitude lower than the toxic dose range for adult animals.
authors.affiliation: Max von Pettenkofer Institut, Federal Health Office (BGA), Berlin, West Germany.
authors.forename: H
authors.initials: H
authors.lastname: Spielmann
authors.forename: R
authors.initials: R
authors.lastname: Vogel
authors.forename: I
authors.initials: I
authors.lastname: Granata
authors.forename: B
authors.initials: B
authors.lastname: Tenschert
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000473:pathology*; D000818:Animals; D001755:Blastocyst / Q000187:drug effects*; D005260:Female; D005865:Gestational Age; D007928:Lethal Dose 50; D008770:Methylnitrosourea / Q000633:toxicity*; D051379:Mice; D011247:Pregnancy
chemical_list: D008770:Methylnitrosourea