[The concentration of endothelin in maternal vein, umbilical vein and artery of normal pregnancy and pregnancy-induced hypertension].

The concentrations of endothelin (ET) in maternal vein (MV), umbilical vein (UV) and artery (UA) of normal pregnancy (N) and severe pregnancy-induced hypertension (sPIH) were measured to investigate the significance of ET in the maternal and feto-placental circulation of normal pregnancy and PIH. 1) The concentrations of ET (pg/ml blood: mean +/- S.E.M.) in MV of a normal non-pregnant group, 1st, 2nd and 3rd trimester of N were 1.00 +/- 0.19 (n = 2), 0.55 +/- 0.16 (n = 4), 0.45 +/- 0.14 (n = 4) and 0.89 +/- 0.09 (n = 10), respectively. The concentration of ET in MV of 3rd trimester of sPIH was 2.76 +/- 1.21 (n = 7), and significantly (p less than 0.05) higher than in MV of 3rd trimester of N. 2) The concentrations of ET in UV and UA of N and UV of sPIH were 1.53 +/- 0.05, 1.29 +/- 0.06, 2.12 +/- 0.46, respectively. The concentrations of ET in UV and UA of N were significantly (p less than 0.01) higher than in MV of N. 3) The concentrations of ET in MV of N and sPIH correlated significantly (p less than 0.05) with diastolic blood pressure of N (r = 0.53). It was concluded that the synthesis of ET during pregnancy was suppressed until the 2nd trimester, and that the increased ET in MV of sPIH might be one of the factors that caused the pathogenesis of PIH. And the high concentration of ET in UV and UA was supposed to operate play a role in feto-placental circulation.