Role of endogenous interleukin-10 in local and distant organ injury after visceral ischemia-reperfusion.

The anti-inflammatory cytokine interleukin (IL)-10 has been detected in serum after visceral ischemia-reperfusion injury and exogenous IL-10 administration has been shown to attenuate the associated distant organ injury. This study was designed to examine the role that endogenous IL-10 production plays on both local and distant organ injury after visceral ischemia-reperfusion injury. Wild-type and IL-10(-/-)-null C57BL/6 mice were subjected to 20 min of supraceliac aortic occlusion or sham laparotomy. Serum and lung tissue cytokine levels (tumor necrosis factor alpha, IL-1beta, IL-6, KC/GRO, and IL-10) were measured after reperfusion (1, 2, and/or 4 h) using either enzyme-linked immunoassay or bioassay. Lung neutrophil infiltration and injury were quantified after reperfusion injury using myeloperoxidase concentration (2 h) and mean capillary permeability (4 h), respectively, whereas the direct liver injury was quantified with serum aspartate aminotransferase levels (1, 2, and 4 h). A subset of IL-10(-/-)-null animals was administered human recombinant IL-10 before the visceral ischemia and lung MPO was measured after reperfusion (2 h). Visceral ischemia-reperfusion in the wild-type and IL-10(-/-)-null mice was associated with in an increase in both serum (IL-1beta, KC/GRO, IL-6) and lung tissue (IL-1beta, KC/GRO) cytokine levels and resulted in lung neutrophil infiltration (myeloperoxidase), lung injury (mean capillary permeability) and liver injury (aspartate aminotransferase). The magnitude of the lung tissue cytokine response (IL-1beta, KC/GRO), neutrophil infiltration, and injury were greater in the IL-10(-/-)-null mice. Exogenous IL-10 resulted in a decrease in the lung neutrophil infiltration in the IL-10(-/-)-null mice. The endogenous IL-10 response to visceral ischemia-reperfusion attenuates the associated lung neutrophil infiltration and injury but has no effect upon either the hepatic injury or the magnitude of the systemic inflammatory response. The beneficial effects of IL-10 may be mediated by the inhibition of IL-1beta and KC/GRO through an endocrine rather than paracrine signal.