TRANSPLACENTAL EFFECT OF STOBADINE ON CYCLOPHOSPHAMIDE-INDUCED MICRONUCLEUS FREQUENCY IN MICE

The transplacental effect of stobadine (STB) on micronucleus (MN) freq uency was studied in fetuses of ICR mice injected with cyclophosphamid e (CP), STB, dissolved in methylcellulose, was administered orally fro m gestational day 11 until day 17 in two concentrations (23.6 and 70.0 7 mg/kg body wt) 2 h prior to CP administration (i.p,, 10 mg/kg body w t). In fetal liver and in maternal bone marrow the frequencies of MN i n polychromatic erythrocytes were significantly decreased in both STB- pretreated groups injected with CP compared to the CP group pretreated with methylcellulose. The higher concentrations of STB was more effic ient, but the difference was not significant. In the CP-treated groups , fetal MN frequencies were about three times higher than in maternal bone marrow, Mouse fetuses thus proved to be far more susceptible to t he clastogenic effect of CP. The protective effect of STB against CP m utagenicicity was confirmed in fetuses of CP-treated female ICR mice, These results are discussed with respect to fetal development and mate rnal/fetal metabolism.