OBJECTIVE: To investigate the protective effect of losartan, an angiotensin II type 1 receptor blocker with antioxidative effect on intestinal ischemia-reperfusion (I/R) injury in rats, against inflammation and apoptotic development. STUDY DESIGN: Forty male Wistar albino rats with a mean weight of 200–250 g each were divided into 4 groups: (1) Sham operation (laparotomy only, sham surgical preparation including isolation of the superior mesenteric artery [SMA] without occlusion), (2) Ischemia model with SMA closure for 2 hours, (3) I/R group (2 hours of ischemia followed by 3-hour reperfusion (SMA occlusion for 120 minutes followed by 240 minutes reperfusion), and (4) Losartan group (2 hours of ischemia, 40 mg/kg losartan was administered to the animals; losartan was dissolved in 1 mL distilled water and administered intraperitoneally after 2 hours of ischemia). Malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels were examined in jejunum tissue. RESULTS: Losartan treatment reduced the I/R-induced increase in MDA levels in the gut. Statistically, while SOD, CAT, and GSH activities decreased significantly in the I/R group, they increased in the I/R+Losartan group. Villus loss and increase in inflammation after ischemia persisted after reperfusion. Losartan treatment played a role in the reduction of inflammation and apoptosis and in the regulation of TNF-α and caspase-9 activity. CONCLUSION: It has been thought that losartan in I/R may reduce mucosal damage and cell apoptosis in the direction of inflammation and may stabilize caspase-9 activity by inhibiting TNF-α stimulus. © Science Printers and Publishers, Inc.