AimTo investigate the effect of niacin on expression of Caveolin-1 in adipocytes and adipose tissue from experimental atherosclerosis rabbits.Methods16 New Zealand white rabbits were fed with high fat diet for 8 weeks, and then randomly divided into two groups: hyperlipidemia group (maintained on high fat diet for 6 weeks, n=8) and niacin treatment group (the same fat diet plus 200 mg/ (kg·d) niacin for 6 weeks, n=8).Rabbits in control group (n=8) were fed with normal diet for 14 weeks.At the end of the study, all rabbits were sacrificed to detect the blood lipid changes and Caveolin-1 expression in adipose tissue by real-time quantitative PCR.The direct effect of niacin on Caveolin-1 mRNA expression in primary rabbit adipocytes was assayed.ResultsCompared with control group, rabbits fed with high fat diet showed higher serum levels of total cholesterol, triglyceride and low density lipoprotein cholesterol, more aorta endometrial thickness and plaque area, less Caveolin-1 expression.Compared with hyperlipidemia group, rabbits treated with niacin showed less serum levels of total cholesterol, triglyceride and low density lipoprotein cholesterol, less aorta endometrial thickness and plaque area and more Caveolin-1 expression.In vitro study, niacin dose-dependenfly stimulated Caveolin-1 expression in cultured adipocytes.ConclusionsNiacin could improve the lipid pro- file and stabilize atheromatous plaque, which may be related to up-regulating the expression of Caveolin-1 in adipose tissue or adipocytes.