RELATION BETWEEN UMBILICAL PROSTACYCLIN PRODUCTION AND BLOOD-FLOW IN THE FETUS

Abstract Umbilical blood-flow (UBF) was measured by ultrasonography in 28 pregnant women. A superfusion preparation was used to investigate the production of 6-keto-prostaglandin F 1α (6-keto-PGF 1α ), a breakdown product of prostacyclin (PGI 2 ) and thromboxane B 2 (TxB 2 ), a breakdown product of TxA 2 , by specimens from the umbilical arteries of the infants born to these 28 mothers and those born to 36 other women in whom UBF had not been measured. UBF was significantly related to 6-keto-PGF 1α production. 6-keto-PGF 1α production was lower in infants of the 8 pre-eclamptic mothers (14·5 ng min -1 g -1 ) than in those of 45 healthy mothers (26·9 ng min -1 g -1 ). Generation of TxA 2 by the umbilical artery was 15-25 times less than that of 6-keto-PGF 1α , and TxA 2 concentrations were unrelated to UBF or the type of pregnancy. These data provide the first evidence for a direct association between blood-flow and PGI 2 generation in human vasculature.