Intravenous immunoglobulin (IVIG) has been found useful in the treatment of various clinical entities and its effect has been associated with inhibition of complement-mediated tissue damage. The aim of this study was to determine the ability of IVIG to protect against mesenteric ischemia-reperfusion (IR)-induced local and remote injury. Rats received vehicle or IVIG (150-600 mg/kg) 5 min prior to sham operation or 30 min of superior mesenteric artery occlusion, followed by 5, 120, or 240 min of reperfusion. IVIG reduced IR-induced mucosal injury without altering IR-induced increases in PMN infiltration or LTB(4) generation. At 5 min post IR, the deposition of IgG and C3 in the lamina propria and surface epithelial cells was attenuated by IVIG. The increased capillary leak, evident at 240 min, was inhibited by IVIG and coincided with a reduction in C3 deposition in lung tissue. The beneficial effects of IVIG may be related to the ability to scavenge deleterious products.