Effects of β3-adrenoceptor on scavenger receptor class B type 1 and its signal transduction pathway in apolipoprotein E knockout mice

It is clear that activated β3-adrenoceptor can improve disorders of lipid metabolism, however there are few reports concerning the anti-atherosclerotic effects of β3-adrenoceptor in the artery of apolipoprotein E knockout (Apoe−/−) mice. In the present study, we aimed at investigating the effects of β3-adrenoceptor on lipids, atherosclerosis plaques, scavenger receptor class B type 1 and its signal transduction in Apoe−/− mice. Ten C57BL/6J mice were used as a control, and fifty age-matched Apoe−/− mice were randomly divided into five groups: atherosclerotic model (saline), positive control (atorvastatin), low-dose β3-adrenoceptor agonist, high-dose β3-adrenoceptor agonist and β3-adrenoceptor antagonist groups. After 26 weeks on the high-fat diet, the mice received the above treatments for 12 weeks. Thoracic aortas, serum lipids, SR-B1, P-MeK1/2, P-ErK1/2 and protein kinase Cα(PKCα) activity were detected. We found that the levels of serum total cholesterol, triglyceride, very low-density lipoprotein/low-density lipoprotein cholesterol and the area of atherosclerotic plaques were significantly decreased in β3-adrenoceptor agonist-treated mice (P