Renal prostacyclin and thromboxane in normotensive and preeclamptic pregnant women and their infants.
In order to investigate whether urinary excretion of prostaglandins (PG) is involved in the pathophysiology of pre-eclampsia, urinary immunoreactive 6-keto PGF1α and TXB2 were measured in normal and preeclamptic women by radio-immunoassay after extraction with Bond Elut column. Urinary levels of 6-keto PGF1α and TXB2 were expressed as ratio of urinary concentration of prostaglandin vs. creatinine (pg prostaglandin/mg creatinine; pg/mg crc.). Urinary excretion in normal pregnant and postpartum women were 211.2±33.8 and 160.1±9.1 pg/mg cre., respectively. In the pre-eclamptic group, urinary excretion of 6-keto PGF1α was 105.3±28.2 pg/mg cre. in pregnancy and 99.0±12.5 pg/mg cre. in the postpartum period. Urinary excretion of 6-keto PGF1α in the pre-eclamptic group was significantly lower (P<0.05) than in normal controls during pregnacy but not in the postpartum period. Urinary excretion of TXB2 was not significantly different between the two groups. The urinary excretion of 6-keto PGF1α was measured before and after the onset of pre-eclampsia in four cases of edema and weight gain of more than 500 g/week (group e), one case of proteinuria of more than 200 mg/dl with edema (group ep) and three cases of pre-eclampsia (group eph). The urinary excretion of 6-keto PGF1α in these eight patients before onset of pre-eclampsia was slightly lower than of normal controls but not significantly so. In group eph, urinary excretion of PG was decreased after the onset of pre-eclampsia. These results provide further evidence of the involvement of PG in the pathophysiology of preeclampsia.