Endothelin-1 levels in the maternal-fetal dyad

• Published in: Gynecologic and obstetric investigation Vol. 39; no. 4; p. 221
• Main Authors: Bracero, L A, Reale, M R, Te, M N, Zeballos, G A, Dweck, H S
• Format: Journal Article
• Language: English
• Published: Switzerland 01.01.1995
• Subjects: Amniotic Fluid - metabolism; Endothelins - blood; Endothelins - metabolism; Female; Fetus - metabolism; Humans; Labor, Obstetric - physiology; Pregnancy; Umbilical Arteries - metabolism; Umbilical Veins - metabolism
• ISSN: 0378-7346
• DOI: 10.1159/000292414

The aim of this study was to determine the distribution of ET-1 levels in the term maternal-fetal dyad. We also compared the levels of ET-1 between umbilical vessels and assessed the effect of labor on the concentration of ET-1. The ET-1 levels were measured in plasma from 18 term maternal-infant pairs. Amniotic fluid ET-1 levels were also measured in 9 of these pregnancies. The ET-1 levels were determined by radioimmunoassay (RIA) after extraction of plasma using Sep-Pak C18 cartridges. There were no significant differences in the ET-1 levels between the umbilical artery and vein. However, there were significant differences in the umbilical artery concentration in women who labored when compared with those delivered without labor (6.0 +/- 1.1 vs. 2.7 +/- 0.7 pg/ml; t test, p = 0.022). ET-1 levels were lowest in the maternal plasma (0.9 +/- 0.2 pg/ml) and highest in the amniotic fluid (83 +/- 15 pg/ml). Assuming that elevated plasma ET-1 levels reflect increased bioactivity, the higher mean ET-1 levels in the cord vessels and in the amniotic fluid when compared to maternal levels suggest a role for ET-1 in the regulation of the fetoplacental circulation and in the constriction of blood vessels in the uterus after parturition. The higher levels of ET-1 in the umbilical artery of women who underwent labor implies that ET-1 is released as a result of the stress of labor.