Arterial baroreflex dysfunction promotes atherosclerosis in rats

The present study was designed to testify the hypothesis that arterial baroreflex dysfunction promotes the development of atherosclerosis. Experiment 1: the baroreflex sensitivity (BRS) was measured in 30 Sprague-Dawley (SD) rats in conscious state with a computerized blood pressure monitoring system. Four weeks later, the rats were administered with Vitamin D-3, and fed with the high-cholesterol diet for 8 weeks to induce atherosclerosis. The hearts and aortae were removed for pathological examination. A negative correlation was found between BRS and the scores of coronary (r= -0.464, P < 0.0 1) or aortic atherosclerosis (r= -0.524, P < 0.01) in SD rats. Experiment 2: sinoaortic denervation (SAD) was performed in SD rats. Then atherosclerosis was also induced. The atherosclerosis scores in SAD rats were significantly higher than those in sham-operated rats (aortic score: 1.50 +/- 0.41 versus 1. 10 +/- 0.39, P < 0.05; coronary score: 1.70 0.35 versus 1.25 +/- 0.54, P < 0.05). Using immunohistochemistry and Western blotting methods, it was found that the expressions of C-reactive protein, intercellular adhesion molecule-1 and vascular-cell adhesion molecule-1 in coronary artery and aorta were increased in SAD rats compared with sham-operated rats. These results indicate that arterial baroreflex dysfunction promotes the development of atherosclerosis in rats, and that inflammation may be involved in this process. (c) 2005 Elsevier Ireland Ltd. All rights reserved.