Uterotropic effect of clofibrate and phenylbutazone in immature female rats

The uterotropic effect of clofibrate and phenylbutazone was studied in immature female rats. A significant increase in the uterine wet weight was observed following clofibrate and phenylbutazone administration. Clofibrate but not phenylbutazone synergized with the uterotropic effect of ethinyl-oestradiol. Phenylbutazone pretreatment significantly decreased the pentobarbitone sleeping time. The uterotropic effect of clofibrate and phenylbutazone might involve displacement of 17-beta oestradiol (or ethinyl oestradiol) from plasma albumin binding sites in rats.