808: Elevated maternal and umbilical arterial 15-hydroxyeicosatetraenoic acid levels and role of 15-hydroxyeicosatetraenoic acid on potassium channels of umbilibal arteries in preeclampsia

To determine if maternal and umbilical arterial 15-hydroxyeicosatetraenoic acid(15-HETE) activities were increased in preeclampsia and the effect of potassium channels on umbilical cord vasoconstriction by 15-HETE in preeclampsia. We used ELISA to measure the activities of 15-HETE of maternal and umbilical arterial sera from normal and preeclamptic pregnancies and tested umbilical artery rings in organ bath experiments. 15-HETE in maternal and umbilical arterial sera were significantly higher in preeclampsia than in normal pregnanies: 2531.3 386.61pg/mL vs 1696.2 476.94 pg/mL (p < 0.01) and 1642 257.16pg/mL vs 1320.6 209.97pg/mL (p < 0.05). 15-HETE-induced vasoconstriction was blocked by KV channel blocker 4-aminopyridine (2 mmol/L). The KATP channel blocker glyburide (1 ìmol/L) and the BKCa channel blocker tetraethylammonium (10 mmol/L) did not extinguish this vasoconstriction. Elevated maternal and umbilical arterial 15-HETE activity and 15-HETE mediated KV channel blocker may explain the exacerbated hypoxic state and the increased vasoconstriction sensitivity in preeclampsia.