INTRAVENOUS-INJECTION OF RABBIT APOLIPOPROTEIN-A-I INHIBITS THE PROGRESSION OF ATHEROSCLEROSIS IN CHOLESTEROL-FED RABBITS

The effects of intravenous injection of purified rabbit apoA-I on the progression of aortic atherosclerosis in cholesterol-fed rabbits were examined. In experiment 1, 28 rabbits were equally divided into groups A and B and fed a 0.5% cholesterol diet for 90 days. For the last 30 days, group B received 40 mg apoA-I every week. The fatty streak lesio ns in group B (23.9 +/- 15.6%) were significantly suppressed compared with those in group A (46.0 +/- 24.9%) (P < .05). In experiment 2, 33 rabbits were divided into four groups (8 or 9 rabbits per group) and f ed a 0.5% cholesterol diet. Group A was killed on day 105, while group s B, C, and D were maintained for an additional 60 days on a normal di et, during which time groups C and D received 1 mg apoA-I every other day or 40 mg apoA-I every week, respectively. The lesions in group C ( 70.2 +/- 15.4%) and group D (65.7 +/- 20.0%) were significantly suppre ssed compared with those in group B (86.2 +/- 13.7%) (P < .05) but wer e not reduced to the level of group A (50.0 +/- 22.9%). Although appar ent regression was not observed under these conditions, the present st udy provided the first evidence for the antiatherogenic effect of homo logous apoA-I on the progression of atherosclerosis in cholesterol-fed rabbits.