EDN1 and endothelial dysfunction: When serum markers of oxidative stress and endothelial dysfunction were compared, severe PE was associated with significantly higher levels of circulating free 8-isoprostane compared to control rats: 369±25 pg/mL for RUPP+HC vs. 281±8 pg/mL for Late-Preg; p<0.01 and ET-1: 0.99±0.25 pg/mL for RUPP+HC vs. 0.46±0.06 pg/mL for Late-Preg; p<0.05.