[Effects of estrogen on serum lipids, plasma endothelin-1, atherosclerosis in ovariectomized rabbits]

To investigate the effects of estrogen on serum lipids, plasma endothelin-1(ET-1) and atherosclerosis in ovariectomized(OVX) rabbits.

Forty-five female rabbits were randomly divided into 5 groups, there are 9 in each: group A: normal control; group B: sham operation + cholesterol feeding; group C: OVX + cholesterol feeding; group D: OVX + cholesterol feeding + estradiol benzoate; group E: OVX + cholesterol feeding + estradiol valerate. The OVX rabbits fed with cholesterol were used as a model for atherosclerosis. After fed for 12 weeks, all rabbits were sacrificed, and the levels of serum lipids, plasma ET-1, atherosclerosis plaque of aorta were measured.

(1) Similar with group B, the total cholesterol (TC) of group D and E [(24.95 +/- 5.31) mmol/L and (27.53 +/- 13.18) mmol/L respectively], were significantly decreased as compared with group C which was (37.69 +/- 4.16) mmol/L. (2) The plasma ET-1 level of group C, which was (343.37 +/- 106.10) ng/L, was significantly higher as compared with group D and E, which were (262.19 +/- 36.45) ng/L [symbol: see text] (245.37 +/- 35.76) ng/L respectively. (3) There were no statistically differences of lipidic sedimentation area among group D, E, and B, which were (17.30 +/- 5.44)% and (36.99 +/- 20.29)% and (29.03 +/- 9.67)% respectively. All of them were significantly decreased as compared with group C, which was (74.83 +/- 12.58)%.

Estrogen may improve the serum lipids, decrease the plasma ET-1 level, and prevent the atherosclerosis of ovariectomized rabbits.