Effects of hypoxia on regulation of prostanoid production in decidual endothelial cells in normal and preeclamptic pregnancy.

Objectives: To examine the effect on prostacyclin and thromboxane production of incubating decidual endothelial cells under hypoxic conditions, comparing cells from normal and preeclamptic pregnancies. Furthermore, to determine whether hypoxia is deleterious to cell growth, and test the effects of stimulation and inhibition on prostanoid production.

Methods: Decidual endothelial cells were exposed for a total of 40 hours to normoxic (20% O2) or hypoxic (2% O2) conditions. Prostacyclin and thromboxane secretion over the final 24 hours of incubation was measured and cell numbers after incubation determined. Lipopolysaccharide (LPS) (1.0 microgram/mL) was used as a stimulator and pirmagrel (1.0 mumol/L) and tranylcypromine (10.0 mumol/L) as prostanoid synthase inhibitors.

Results: Incubations in hypoxia resulted in increased thromboxane (P < .05) but no change in prostacyclin production. This thromboxane increase was abrogated by pirmagrel. LPS caused significant stimulation of prostacyclin and thromboxane secretion and both LPS and hypoxia resulted in lower cell numbers. Decidual endothelial cells from normal and preeclamptic pregnancies were generally not different.

Conclusions: This study indicates that in preeclampsia, where decidual endothelial cells are in a relatively more hypoxic environment, thromboxane production by these cells is likely to be increased and the prostacyclin/thromboxane ratio decreased. The thromboxane synthase inhibitor, pirmagrel, was able to reverse this abnormal increased secretion of thromboxane in vitro.