Sex difference in the inhibitory effect of aspirin on prostacyclin production of rat aortae.

The effect of aspirin on the prostacyclin (PGI2) production of rat aorta was investigated, and the influence of sex hormones on the effect of aspirin was studied by the treatments of hormone administration, ovariectomy and castration. There was no significant sex difference in the arterial production of PGI2 between male and female rats. However, the PGI2 production was decreased with aspirin treatment, and the effect of aspirin was more efficient in male rats. The inhibitory effect of aspirin was reduced in the rats treated with estradiol and the castrated male rats, but it was potentiated in the rats treated with testosterone and the ovariectomized female rats. These results suggest that sex hormones may regulate the effect of aspirin on the PGI2 production in the aorta.