MINIMAL IMMUNOLOGICAL CHANGES IN STRUCTURALLY MALFORMED RATS AFTER PRENATAL EXPOSURE TO CYCLOPHOSPHAMIDE

In order to compare the sensitivities of morphological and immunologic al parameters in a teratology study, effects in day 20 rat fetuses wer e studied after a single exposure to the immunosuppressive cytostatic agent cyclophosphamide (CP) on either day 11 or day 15 of gestation. T eratological methods included evaluation of external and skeletal morp hology. Furthermore histology, immunohistochemistry and flow cytometry were performed on fetal thymus, liver and spleen. Immune function was assayed using the Trichinella spiralis infection model. Treatment res ulted in dose-dependent gross morphological malformations, and in addi tion in overt skeletal anomalies such as brachygnathia, wavy ribs, and lordosis. In contrast, the immunological parameters tested revealed o nly minimal differences between treated and control groups. These resu lts suggest either a remarkable recovery of the immune system after tr eatment, or a relatively high resistance of the immune system to the p resent treatment.