The effect of 17 beta-estradiol and endothelin 1 on prostacyclin and thromboxane production in human endothelial cell cultures.

The effect was investigated of endothelin 1 and 17 beta-estradiol on prostacyclin and thromboxane A2 production (determined as the stable metabolites 6-keto-PGF1 alpha and thromboxane B2, respectively) in endothelial cell cultures obtained from veins of human umbilical cord. There was a statistically significant increase of 6-keto-PGF1 alpha production with endothelin 1 at concentrations of 10(-8) and 10(-9) M [9.5 +/- 1.1% and 7.2 +/- 0.9%, (mean +/- SD, n = 5), respectively] compared to basal production. In contrast, 17 beta-estradiol alone (10(-6) and 10(-8) M) had no effect. In the presence of 17 beta-estradiol (10(-8) M) the stimulating effect of endothelin 1 (10(-8) and 10(-9) M) on 6-keto-PGF1 alpha production was further enhanced to 60.0 +/- 22.5% and 39.5 +/- 22.1%, respectively, compared to basal values. With respect to thromboxane B2, no change in its production was observed by the addition of endothelin 1 and 17 beta-estradiol, alone or in combination in the concentrations mentioned above. These results indicate that 17 beta-estradiol potentiates the effects of endothelin 1 on prostacyclin production in human endothelial cells.