PREECLAMPSIA DOES NOT ALTER THE RESPONSE TO ENDOTHELIN-1 IN HUMAN OMENTAL ARTERY

Endothelin-1 (ET-1), known to be present in high concentrations in ser um from pre-eclamptic compared with normotensive pregnant women, may c ontribute to the increased vascular reactivity seen in preeclampsia. E xperiments were designed to compare the contractile activity of ET-1 i n isolated omental arteries from menopausal women (n = 6), normotensiv e pregnant women (n = 7), and pre-eclamptic patients (n = 7). Intact r ings (3-mm width) were suspended for isometric tension recording in or gan chambers filled with modified Krebs/bicarbonate buffer aerated wit h 95% air and 5% CO2, 37 degrees C, pH 7.35-7.4, under tension of 1 g. No significant differences were found in either the sensitivity to (c oncentration producing 50% of contraction) or efficacy of (maximal inc rease in tension, normalized to reference contraction to KCl) ET-1 in the vessels of all three groups of patients studied. These data argue against ET-1 as a primary factor in pre-eclampsia. The modulatory role of ET-1 on the effects of other contractile factors of human blood, a s a possible cause of pre-eclamptic changes, remains to be elucidated.