Relationship of collagen content, intimal thickening and angiotensin II level of iliac arteries after balloon injury in rabbits / 浙江大学学报·医学版

ABSTRACT

OBJECTIVE: To investigate the relationship of collagen content intimal thickening and angiotensin II level of iliac arteries after balloon injury in rabbits. METHODS Fifty male New Zealand white rabbits were randomly devided into 6 groups losartan groups, benazapril groups and control groups for 4 weeks or 8 weeks. Every rabbit underwent endothelial debridement of the right iliac artery. lorsartan (15 mg/kg/d) and benazapril (5 mg/kg/d) were orally administrated respectively in losartan groups and benazepril groups from 5 days before until 4 weeks or 8 weeks after balloon injury. RESULTS: Collagen content and intimal area of rabbit iliac arteries were increased after balloon injury. After intervention for 4 weeks with losartan and benazapril, collagen content was decreased in losartan and benazapril groups than in control group 23.58+/-6.16 % and 22.67+/-10.20 % compared with 35.20+/-7.25 % respectively, P<0.05. After intervention for 8 weeks, collagen content was significantly decreased (20.69+/-11.16)% and 25.41+/-11.00 % compared with 42.69+/-13.99 % respectively, P<0.05; Intimal area and intimal to medial area ratio were also decreased in losartan and benazapril groups than in control group; Lumen area was increased in losartan and benazapril groups than in control group(0.79+/-0.25)mm2 and (0.76+/-0.28)mm2 compared with (0.62+/-0.27)mm2 P<0.05; Tissue angiotensin II level was increased in losartan group (516.31+/-70.79)pg/mg.pro compared with (410.72+/-100.11)pg/mg.pro, P<0.05, and decreased in benazapril group than in control group (340.62+/-67.69)pg/mg.pro compared with (410.72+/-100.11)pg/mg.pro, P<0.05. There were close correlation between tissue angiotensin II level and intimal area, or between tissue angiotensin II level and intimal to medial area ratio, or and collagen content in benazapril group, respectively, P<0.05. Conclusion (1) Collagen protein is a dynamic participant in vascular injury. (2) Tissue renin angiotensin system may play an important role in collagen accumulation, intimal thickening and vascular injury after angioplasty. (3) Losartan and benazapril reduce vascular collagen content and inhibit intimal thickening after balloon injury.