Intraperitoneal enalapril ameliorates morphologic changes induced by hypertonic peritoneal dialysis solutions in rat peritoneum.

Peritoneal fibrosis (PF) is one of the most serious causes of technique failure in long-term peritoneal dialysis (PD). Although the mechanisms responsible for the genesis of PF are not well understood, angiotensin II is known to promote fibrosis and inflammation in various tissues and angiotensin converting enzyme inhibitors (ACEIs) have been shown to attenuate those effects. We previously showed that ACEIs have beneficial effects on peritoneal alterations induced by hypertonic (3.86% glucose) PD solutions. In the present study, we investigated the local effects of intraperitoneal (IP) enalapril on peritoneal alterations induced by 3.86% glucose PD solution in rats on chronic PD. One week after peritoneal catheter insertion, 23 non uremic male rats were randomly divided into two groups: group A (n = 11) received 20 mL 3.86% PD solution twice daily, and group B (n = 12) received 20 mL 3.86% PD solution containing 1 mg/L enalapril twice daily. After 4 weeks of such infusions, we measured net ultrafiltration (UF) volume and obtained samples of visceral peritoneum from the liver for thickness measurement. Net UF was significantly higher (6.6 +/- 0.2 mL vs. 5.6 +/- 0.2 mL) and peritoneal thickness was significantly lower (30 +/- 5 microm vs. 52 +/- 0.8 microm) in group B. We conclude that intraperitoneal enalapril (an ACEI) protects the peritoneal membrane from the effects of hypertonic glucose. This protection might be mediated by enalapril's interference with angiotensin though inhibition of cytokine overexpression.