Heat-shock protein-73 protects against small intestinal warm ischemia-reperfusion injury in the rat

Background. The protective effects of heat-shock protein (hsp) in rat small intestinal warm intestinal warm ischemia-reperfusion (I/R) injury are poorly understood. Methods. Hsp-73 expression was induced in rat small intestine with use of sodium arsenite injected (6 mg/kg) through a catheter cannulated into the left common carotid artery 24 hours before ischemia (group I). In the control group an equal volume of phosphate-buffered saline solution was injected (group 2). To block the induction of hsp-73 expression, sodium arsenate and quercetin (5 mg/kg) were injected (group 3). Results. The mean peak plasma levels of tumor necrosis factor-alpha and cytokine-induced neutrophil chemoattractant after reperfusion were lower in group 1 than in group 2. The tissue myeloperoxidase activity after reperfusion was lower in group 1 than in group 2. The mean peak plasma level of interleukin-10 after reperfusion was higher in group 1 than in group 2. The induction of hsp-73 expression reduced the synthesis of nitric oxide and the magnitude of the small intestinal warm I/R injury. The results in group 3 were similar to those in group 2. Conclusion. Hsp-73 protects against small intestinal warm I/R injury by inhibiting the synthesis of inflammatory cytokines and the activation of neutrophils and by accelerating the synthesis of antiinflammatory cytokines.