EFFECTS OF THE ANGIOTENSIN-CONVERTING ENZYME-INHIBITOR ENALAPRIL ON BACTERIAL TRANSLOCATION AFTER THERMAL-INJURY AND BACTERIAL CHALLENGE

Burn injury and sepsis produce acute gastrointestinal derangements tha t may predispose patients to bacterial translocation. We studied the e ffects of enalapril, an angiotensin converting enzyme inhibitor (ACEi) , on gastrointestinal anatomic alterations, bacterial translocation, a nd related mortality during gut-derived sepsis in burned mice that had received a prior bacterial challenge. BALB/c mice (n = 111) were trea ted with enalapril 10 or 1 mg/Kg body weight or sterile saline as cont rol twice daily for 3 days. They were then gavaged with 10(9) In-111 r adiolabeled or unlabeled Escherichia coil and given a 20% total body s urface area (TBSA) burn injury. Animals gavaged with unlabeled bacteri a were observed for survival (n = 60). Survival was significantly high er in the group receiving enalapril 10 mg/Kg compared with control (75 % vs. 10%). Mice treated with enalapril maintained small intestine wei ght, measured 4 h postburn, and ileal mucosal height was preserved, wh ereas burned untreated animals lost intestinal weight and mucosal heig ht. Bacterial translocation was decreased in mice treated with enalapr il, but killing was unaffected. This study suggests that treatment wit h enalapril positively affects the outcome in gut-derived sepsis by am eliorating gastrointestinal structural and functional damage and decre asing bacterial translocation.