Effects of rilopirox on rabbit blastocysts in a protein-free in vitro culture under different culture conditions.

The effect of rilopirox (Hoe 351, CAS 104153-37-9) on rabbit blastocysts in vitro was studied. Blastocysts of day 6 post coitum were cultured in Ham's F 10 medium supplemented with polyvinylpyrrolidone using different concentrations of rilopirox with and without serum proteins. In culture conditions without serum proteins there were no differences in the growth rates of the blastocysts after 24 h of culture in the presence of 1 microgram/ml of rilopirox. However, 5 micrograms/ml of rilopirox resulted in a significant reduction of the mean growth rate as well as in a serious morphological damage of the treated blastocysts. Purified human serum albumin could partly prevent this toxic effect, while complete human serum and foetal calf serum did not show this characteristic. Analyses of the protein synthesis of the blastocysts treated with rilopirox by two-dimensional gel electrophoresis and subsequent fluorography did not show any differences in comparison to the untreated controls, despite of obvious morphological alterations.