The effect of denervation on ischemia reperfusion injury on skeletal muscle

Many agents were studied for the prevention of Ischemia-Reperfusion (IR) injury but few of them are used in clinical cases. Denervation can reduce the energy consumption of a skeletal muscle and theoretically can increase its ischemia tolerance. In this study the effects of precontioning by surgical or chemical denervation with Botulinum Toxin A (BTx-A) on IR injury of a skeletal muscle was examinedBiceps femoris muscle of 42 Wistar Albino rats were used in this study. Only IR injury was done in control group. In groups 2-4, surgical denervation was done 30 days (n=6), 7 days (n=6) and 1 day prior to IR injury. In groups 5-7 chemical denervation with BTx-A was applied 30 days (n=6), 7 days (n=6) and 1 day prior to IR injury. For IR injury tourniquet was applied to right extremity of all rats for four hours. Then tourniquet was cut and reperfusion was allowed for 4 hours. Then all the animal were sacrificed and tissue samples were gathered. In these tissues histological examination, apoptosis presence with Caspas 3 stains, tissue malonyldialdehyde (MDA) and nitrit + nitrate levels were studiedThe degenerative histology and apoptosis scores were not significantly decreased in groups that the surgical or chemical denervation was done 30 days prior to surgery. But the decrease was significant in tissue biochemical analysis in both groups. All the histological, apoptotic and biochemical parameters were significantly decreased in groups that surgical or chemical denervation was done 7 days prior to IR injury. Although the degenerative histology and tissue NOx scores were significantly decreased in groups that surgical or chemical denervation was done 1 day prior to IR injury, decrease in tissue MDA level in one day prior surgical denervation group and apoptosis score level in one day prior chemical denervation groups were not statistically significantIn conclusion, in a skeletal muscle; surgical or chemical denervation that applied at least one day prior to IR injury can increases the muscle tolerance for ischemia and reduces the effects of reperfusion injury. Chemical denervation with BTx-A can be a better choice for providing similar results without a secondary operation.