The effects of ischemic preconditioning on the expression of NF-κB in lung after ischemia-reperfusion injury

Objective To investigate the effects of ischemic preconditioning on the expression of nuclear factor-κB(NF-κB) in lung after lung ischemia-reperfusion (I/R) in rats and to study the possible role of ischemic preconditioning in the mechanism of attenuating I/R injury. Methods Thirty-six male Sprague-Dawley rats were randomized into three groups (twelve for sham operation ,twelve for ischemia-reperfusion, twelve for ischemic preconditioning ).I/R injury consisted of 45 minutes of lung cross-clamping followed by 2 hours (or 5 hours )of reperfusion ; for ischemic preconditioning three cycles of 5 minutes of ischemia and 5 minutes of reperfusion were applied immediately preceding I/R; sham operation animals had a thoracotomy only. Lung tissue wet-to-dry weight ratio (W/D), Expression of NF-κB in lung was observed by immunohistochemical stain and image analysis . The pathological change of lung tissue was observed under light microscopy. Electron microscopic evaluation was done on randomly selected lungs of two rats in each group at the end of the experiment. Results Expression of NF-κB decreased significantly after ischemic preconditioning (P0.01). Conclusions Ischemic preconditioning can inhibit the expression of NF-κB after I/R injury, and attenuate ultrastructure injury of lung tissue, then relieve pulmonary edema, and protect lung from ischemia-reperfusion injury.