The ACE inhibitor, quinapril, ameliorates peritoneal fibrosis in an encapsulating peritoneal sclerosis model in mice

Encapsulating peritoneal sclerosis (EPS) is a serious complication of patients on continuous ambulatory peritoneal dialysis. In the present study, the inhibitory effect of angiotensin-converting enzyme inhibitor, quinapril, on the peritoneal fibrosis was examined in an experimental EPS model in mice. C57BL/6 mice were divided into three groups. Group 1 (n=20) mice received daily intraperitoneal injection of 0.3 ml of SH solution which consists of 0.1% chlorhexidine gluconate and 15% ethanol dissolved in saline. Group 2 (n=20) and group 3 (n=20) mice received SH solution by the same manner of group 1 mice, and were given orally 1 or 3 mg kg(-1) of quinapril, respectively, on daily basis. Five mice from each group were sacrificed on day 3, 7, 21, and 56, and evaluated macroscopically and histologically. Macroscopic examination revealed that fibrotic change in parietal peritoneum in group 1 was more severe than in group 2 and 3, accompanied with statistical significance. Histological examination demonstrated that peritoneal thickening in group 2 and 3 were markedly ameliorated than in group 1. Semi-quantitative analysis showed that histological fibrotic score was significantly higher in group 1 than in group 2 and 3. These results suggest that quinapril ameliorate the fibrotic change in parietal peritoneum in experimental EPS model in mice, and may have a clinical utility for the prevention of EPS.