Effect of Conditioned Ischemic Stresses on NF-kappaB Activation in Rat Skeletal Muscle

ABSTRACT

OBJECTIVE: To investigate the effect of conditioned ischemic stresses on NF-kappaB activities and the protective role of genistein in rat skeletal muscle. METHOD: Rectus femoris muscles of rats were divided into 4 groups according to conditioned ischemic stresses as followings sham-operated control group; 2 hour ischemia group by clamping the proximal femoral vessel; ischemia-reperfusion group by 30 minutes of reperfusion following 2 hours of ischemia; ischemia-reperfusion-electrical nerve stimulation group in which current was applied at the femoral nerve during 30 min of reperfusion period to induce repetitive muscle contraction. Either genistein-5% dimethyl sulfoxide (DMSO) or DMSO was injected 2 hours before ischemic induction. NF-kappaB activities were analysed by electrophoretic mobility shift assay. RESULTS: NF-kappaB activities pretreated with DMSO were significantly increased in ischemia, ischemia-reperfusion and ischemia-reperfusion-electrical nerve stimulation group compared with those of control group and in ischemia-reperfusion-electrical nerve stimulation group compared with those of ischemia group. Muscle edema was increased in ischemia-reperfusion-electrical nerve stimulation group. But, NF-kappa activities and muscle edema pretreated with genistein were attenuated in ischemia-reperfusion-electrical nerve stimulation group compared with those pretreated with DMSO alone. CONCLUSION: NF-kappaB activities reflect the severity of ischemic stresses. Pretreatment with genistein can attenuate NF-kappa activities and muscle edema in ischemic stress of rat skeletal muscle.