Plasma renin activity, angiotensin II, prostacyclin and thromboxane A2 concentrations in 139 preeclamptic patients

Plasma renin activity, plasma concentrations of angiotensin II (AngII), stable metabolites (6-keto-prostaglandin F1 alpha: 6-keto-PGF1 alpha) of prostacyclin (PGI2) and a metabolite (thromboxane B2: TXB2) of thromboxane A2 (TXA2) were measured with radioimmunoassay(RIA) in 107 normal pregnancy (control) and 139 preeclamptic patients in 28-41 gestational weeks. PRA and 6-keto-PGF1 alpha were significantly higher and AngII was slightly higher in preeclampsia than in control, and TXB2 was significantly lower in preeclampsia in control. The ratio of 6-keto-PGF1 alpha/TXB2 was significantly lower in preeclampsia than in control. These data suggest that the changes in the renin-angiotensin system may not be primary alterations in preeclampsia. It can be speculated that in preeclampsia the changes in absolute concentrations of 6-keto-PGF1 alpha and TXB2 are less important than the decrease in the ratio of the 6-keto-PGF1 alpha/TXB2.