Cyclophosphamide increases the frequency of sister chromatid exchange in direct preparations of human chorionic villi in the absence of supplementary enzymatic activation systems.

A study was performed to evaluate the effect on the frequency of sister chromatid exchange in first trimester chorionic villi of two chemical compounds, mitomycin C and cyclophosphamide. Mitomycin C is generally known to induce an increase in sister chromatid exchange both in vivo and in vitro standard conditions. Cyclophosphamide is a compound requiring additional enzymatic enrichment of the culture medium to express its mutagenic activity under in vitro conditions. We exposed chorionic villi samples to these chemicals without the use of conventional cell cultures and without adding enzymatic extracts to the medium. The results indicate a statistically significant increase in the frequency of sister chromatid exchange after exposure to both compounds and also at lower dosages.