Raloxifene and estrogen reduces progression of advanced atherosclerosis--a study in ovariectomized, cholesterol-fed rabbits.
The present study investigated the effect of raloxifene, a selective estrogen receptor modulator (SERM), on aortic atherosclerosis in 80 ovariectomized, cholesterol-fed rabbits with pre-induced atherosclerosis. The animals were fed an atherogenic diet containing 240 mg cholesterol/day for 15 weeks, after this period a baseline control group was sacrificed. Thereafter, oral treatment was initiated with either estradiol 4 mg/day (n=20), raloxifene (210 mg/day) or placebo (n=20). In the treatment period of 39 weeks, the dietary cholesterol content was reduced to 80 mg cholesterol/day. Postmortem evaluation showed a significantly increased uterine weight induced by estradiol treatment (10.3+/-1.2 g), whereas raloxifene intervention caused a decreased uterus weight (1.21+/-0.1 g) when compared to placebo (2.48+/-0.47 g). Throughout the study, serum lipids increased in all groups to levels seen in very high risk humans. After 58 weeks the cholesterol content in the aorta was 3.18+/-0.54 micromol/cm(2) (38% reduction) in the estradiol group, 3.66+/-0.52 micromol/cm(2) (29% reduction) in the raloxifene group and 5.12+/-0.60 micromol/cm(2) in the placebo group. Analyses of the aortic cholesterol content corrected for time-averaged serum cholesterol revealed that both estradiol and raloxifene therapy significantly reduced the progression of atherosclerosis (P<0.01 for both) as compared to placebo.
Bjarnason
N H
NH
Center for Clinical and Basic Research, Ballerup Byvej 222, 2750, Ballerup, Denmark. nb@ccbr.dk
Haarbo
J
J
Byrjalsen
I
I
Alexandersen
P
P
Kauffman
R F
RF
Christiansen
C
C
D000818:Animals; D001161:Arteriosclerosis / Q000188:drug therapy* / Q000209:etiology*; D002791:Cholesterol, Dietary; D018450:Disease Progression; D004958:Estradiol / Q000627:therapeutic use*; D005260:Female; D010052:Ovariectomy; D011817:Rabbits; D020849:Raloxifene Hydrochloride / Q000627:therapeutic use*; D020845:Selective Estrogen Receptor Modulators / Q000627:therapeutic use*
D002791:Cholesterol, Dietary; D020845:Selective Estrogen Receptor Modulators; D020849:Raloxifene Hydrochloride; D004958:Estradiol