Preeclampsia activates 15-lipoxygenase and its metabolite 15-hydroxyeicosatetraenoic acid enhances constriction in umbilical arteries.

Objective: To compare the differential expression of 15-lipoxygenase (15-LO) isoenzymes, 15-LO-1 and 15-LO-2 in preeclampsia (PE), and normal pregnancy and its metabolite 15-hydroxyeicosatetraenoic acid (15-HETE) on the vasoconstriction of human umbilical artery (HUA) rings. Study design: We performed western blotting and isometric tension studies and t-test analysis on data from 6 women with normal pregnancy and 8 women with PE. Results: Expressions of 15-LO-1 and 15-LO-2 in placentas and HUA rings in PE increased more than that in normal groups (P < 0.01). 15-HETE increased HUA rings tension in a dose-dependence manner, which were significantly greater in PE than in normal pregnant controls (P < 0.01). However, the constriction of HUA rings was completely eliminated by 2-aminoethoxydiphenyl borate (2-APB) in both normal pregnancy and PE (P < 0.01) and attenuated partly by nifedipine in dose-dependence in normal pregnancy (10(-8) mol/L P > 0.05; 10(-7), 10(-6) mol/L P < 0.05) and in PE (P < 0.01). Conclusion: PE upregulates 15-LO pathway via 15-HETE, which increased intercellular calcium level to cause constriction of HUA rings. (C) 2011 Elsevier Ltd. All rights reserved.