Vasospastic Action of Serotonin on the Umbilical Artery in Normal and Preeclamptic Patients

Abstract

The purpose of this study was to determine whether elevated plasma-free-serotonin (5-HT) levels in preeclampsia could evoke abnormal vasoconstriction in the umbilical artery (UmA). Threshold concentrations of 5-HT in the UmA from 12 normal pregnant (NP) women were 5 ng/ml. Plasma-free 5-HT levels in the UmA (14.38 +/- 5.68 ng/ml) in severe preeclampsia (SP) were higher than the threshold value. Plasma-free 5-HT levels in UmA blood (1.6 +/- 1.2 ng/ml) in NP women were lower than the threshold value. There were significant increases in sensitivity to 5-HT in the UmA from SP; the threshold value of 5-HT was low (1.0 ng/ml), and the EC50 value (5.2 +/- 2.4 ng/ml) was significantly lower than that of NP women (13.9 +/- 3.0 ng/ml, p < 0.001). These results strongly suggest that increased plasma-free 5-HT and vascular hypersensitivity to 5-HT in preeclampsia can cause vasospasms and a disturbance of the feto-placental circulation.