Plasma endothelin-1 (ET-1) and atrial natriuretic peptide (ANP) concentrations were determined in 83 cases, including 30 cases of PIH and 30 normal pregnant women during their third trimester, and 23 non-pregnant women as controls.
Results: compared to the non-pregnant women and normal pregnant women in their late pregnancy, the concentrations of plasma ET-1 and ANP were significantly increased in patients with PIH; after administration of magnesium sulfate infusion, the decrease of ET-1 and ANP concentrations was statistically significant in PIH cases, while there was no change in normal late pregnancy. In PIH patients, the score index of PIH had significant positive correlation with the level of plasma ET-1 (r = 0.717, P < 0.01). There were also positive correlations between the mean arterial pressure and the level of plasma ET-1 in PIH, normal pregnant and non-pregnant women (r = 0.613, P < 0.01; r = 0.441, P < 0.05; r = 0.586, P < 0.01). We failed to find any association between the concentrations of ET-1 and ANP in all 3 groups (r = 0.247, r = 0.384, r = -0.227; P > 0.05).
Conclusion: ET-1 acts as an important physioregulatory factor of blood pressure, and its increase may be responsible for the development of PIH, and may serve as an indicator of the severity of PIH.