Embryotoxic effect of cyclophosphamide after being biotransformed in a culture of postimplantation rat embryos

Biotransformation of cyclophosphamide to teratogenous products in the presence of the rat hepatic microsomal fractions and NADP.H2 was carried out in the medium for cultivation of postimplantational rat embryos. Nontoxic concentrations of all components participating in the reaction and threshold concentrations of cyclophosphamide were defined. The results obtained were compared with the data of the drug action on the embryos of the same age developing in the maternal body. The developmental anomalies appeared to be similar in both cases. The method for detecting the teratogenous products of cyclophosphamide bioactivation in the culture has been demonstrated to be highly sensitive as compared with the standard biological tests.