IMMUNOREACTIVE ENDOTHELIN CONCENTRATIONS IN MATERNAL AND FETAL BLOOD

Immunoreactive-endothelin (ir-ET) concentrations were determined in peripheral maternal blood and in umbilical cord blood just after delivery. The concentrations in both the umbilical artery (2.83 ± 1.36 pmol/1 plasma, Mean ± SD) and vein (3.37 ± 1.53 pmol/1) were significantly higher than those found in maternal venous blood (1.43 ± 1.02 pmol/1). On the other hand, ir-ET levels in maternal blood were not significantly different when compared with those found in non-pregnant women (1.50 ± 0.83 pmol/1). No significant difference of ir-ET levels between the umbilical artery and vein was observed. A highly significant correlation (r = 0.60, p<0.01) of ir-ET levels between the umbilical artery and vein was observed. Also, a significant correlation (r = 0.48, p<0.01) between umbilical vein and maternal vein ir-ET levels with a weaker correlation (r = 0.36, p<0.05) between umbilical artery and maternal vein ir-ET levels was demonstrated. The present study indicates that ir-ET may be actively secreted in fetal circulation and the plasma levels in maternal and fetal circulation may have a possible relation. © 1990.