[Circadian rhythm studies on the prenatal toxic effect of cyclophosphamide and centrophenoxine in Wistar rats].

According to the literature, centrophenoxine weakens the teratogenic effect of cyclophosphamide. Circadianrhythmic examinations were carried out on Wistar-rats at 4 different times daily during embryogenesis. The spectrum of deformities induced by cyclophosphamide showed significant differences according to the stage of development and the time of day. The protective effect of centrophenoxine has been demonstrated, but its ability to do so also showed daytime fluctuations. The most remarkable effect was obtained 14 d post coitum at one in the morning. The importance of circadianrhythmic examinations in experimental work is therefore stressed, and should be given some more attention.