Cytotoxic effects of soluble factor in preeclamptic sera on human trophoblasts

Evidence indicating abnormal biological behavior of trophoblasts has been s een in preeclamptic patients, but the mechanism is still unknown. We have p reviously shown that endothelial injury and neutrophil activation are-induc ed by certain factors in preeclamptic sera. We investigated the effect of s era from eight preeclamptic and 11 normal pregnant women on cellular prolif eration and viability of trophoblasts. using H-3-thymidine incorporation an d the trypan-blue dye exclusion test, respectively. Five of eight preeclamp tic sera, but none of the normal pregnant sera, inhibited H-3-thymidine inc orporation. The trypan-blue test revealed the sera reduced cellular viabili ty. Gel permeation showed that the greatest growth-inhibitory activity corr esponded to a molecular weight of 50 kDa. The serum-mixing test revealed th is permeation and inhibitory preeclamptic sera suppressed the growth-promot ing activity of normal pregnant sera in a dose-dependent manner. These resu lts suggested the presence of certain factors in some preeclamptic sera tha t can affect cellular behavior of human trophoblasts.