Abstract:

Objective To investigate the effects of renin inhibitor, Aliskiren on atherosclerosis (As) and As inflammation. Methods Rabbit As model was established by high fat diet, and 24 New Zealand rabbits were randomly divided into single high fat group (n=8), Aliskiren group (n=8) and normal control group(n=8). Rabbits in single high fat group were fed with high fat diet (1.5% cholesterol+5% lard oil), those in Aliskiren group were fed with high fat diet and Aliskiren (25 mg·kg^－1·d^－1), and those in normal control group were fed with regular diet. Rabbits were fed for 16 weeks, and were sacrificed. Thoracic aorta samples were obtained for histological examination, and immunohistochemistry was used to detect the expression of biomarkers of macrophages and smooth muscle cells (RAM11 and α-actin) and lectin like oxidized LDL receptor-1 (LOX-1) in plague, which were indicated as ratios of area of positive expression. Results Histological examination with oil red O staining revealed that the area of plaque in Aliskiren group was significantly lower than that in single high fat group [(34.38±2.07)% vs (47.12±4.16)%, P<0.01]. Immunohistochemical detection indicated that the ratios of cells with positive expression of RAM11 and LOX-1 protein in plaque in Aliskiren group were (21.13±2.10)% and (11.38±1.69)% respectively, which were significantly lower than those in single high fat group [(30.63±2.26)% and （16.75±1.67）% respectively] (P<0.01, P<0.05). Spindle smooth muscle cells with positive expression of α-actin were observed in plaque in single high fat group and Aliskiren group, which mainly located in intima and media. Conclusion Aliskiren inhibits the progression of As, and reduces inflammatory response in plaque.

Key words: renin inhibitor, Aliskiren, inflammation, plaque, atherosclerosis