Cyproterone acetate could counteract the benefits of estradiol valerate in oophorectomized cholesterol-fed rabbits.

Abstract

The administration of hormonal replacement treatment to women with an intact uterus needs to be supplemented with progestogenic compounds to avoid endometrial hyperplasia. However, progestins may cancel the beneficial effects of estrogens on the cardiovascular system. The goal of this study was to examine the effects of adding cyproterone acetate to estradiol (E(2))on aorta atherogenesis. Thirty-two cholesterol-fed New Zealand white rabbits were studied for 4 months. The animals underwent laparotomy and were randomly allocated to four groups. Twenty-four rabbits underwent bilateral ovariectomy, and the other eight were sham-operated (group S). The ovariectomized rabbits were allocated to three groups of eight animals each receiving E(2) valerate (group E), E(2) valerate plus cyproterone acetate (group EC), or placebo after sterilization (group C). After 4 months, the cholesterol-rich diet caused atherosclerotic aortic lesions in both treated groups that affected 17.91% +/- 10.19% and 28.16% +/- 7.97% of the aortic surface of groups E and EC, respectively, with a markedly lower aortic plaque size in group E than in groups C and S. Rabbits from group E (but not from group EC) had aortic cholesterol content significantly lower than rabbits from the sham-operated and control groups. E(2) valerate reduces aortic atheromatosis in cholesterol-fed, ovariectomized rabbits, and the addition of cyproterone acetate may neutralize this effect.