Plasma adenosine levels and P-selectin expression on platelets in preeclampsia

Objective: To measure the correlation of plasma adenosine levels with plate let activation in women with preeclampsia. Methods: Plasma adenosine concentration and expression of P-selectin, a mar ker for platelet activation, were measured in 18 normal pregnant women and 18 preeclamptic women. The effect of 8-sulfophenyltheophylline, an adenosin e receptor blocker, on expression of P-selectin on platelets also was measu red. Results: Plasma adenosine level averaged 0.77 +/- 0.11 muM (standard error of the mean [SEM]) in women with preeclampsia, significantly higher than th e mean level of 0.47 +/- 0.08 muM in women with normal pregnancies (P < .05 ). Expression of P-selectin on platelets averaged 7.8 +/- 1.2% in women wit h preeclampsia, also significantly higher than the mean level of 4.7 +/- 0. 7% in normal pregnancy (P < .05). Adenosine receptor blockade significantly increased expression of P-selectin on platelets in women with preeclampsia by 26% (P < .05), which was significantly higher than the 13% increase of activation in those with normal pregnancies (P < .05). Conclusion: Adenosine is an established platelet activation suppressor. Inc reased plasma levels of adenosine in preeclampsia might partially compensat e and tend to prevent further excessive platelet activation in women with p reeclampsia. (C)2001 by The American College of Obstetricians and Gynecolog ists.