| Background and ObjectivePeripheral nerves comprise all of the cranial nerves which apart from the olfactory nerve and optic nerve,spinal nerves,autonomic nerves and their ganglion.Peripheral nerve injury is common in clinical,however,it is difficult for the nerve regeneration and the peripheral nerve injury is one of the leading cause for the disabled and defuctionalization.Therefore,the regeneration of peripheral nerve injury has always been a tough and hot issue in clinical and scientific field.In recent years,even though the rapid development of the microsurgical technology provide a favorable technical support for the repair and regeneration of injuried nerves,the therapeutic effects still have some limitations owing to the specificity of the anatomical and function of peripheral nerves,and the treatment effects and safety of cytokines,gene molecule and tissue engineering is still need to be further studied.Acupuncture and moxibustion therapy is the inheritance of traditional medicine in China,which has been confirmed by a large number of studies can promote the rehabilitation of peripheral nerve injury and the recovery of limb function after injury.Electroacupuncture therapy is an emerging physiotherapy technology which developed by acupuncture and moxibustion,several clinical studies have shown that electroacupuncture therapy can promote the regeneration of peripheral nerve injury and is benefical to the reconstruction of the body's function,but it still needs further studied for its mechanism.The aim of this study was to investigate the effect of electroacupuncture therapy on neurogenesis and denervation of skeleton muscle atrophy in rats after sciatic nerve injury,and to further explore the mechanism of electroacupuncture therapy on the regeneration of peripheral nerve injury and denervation of skeleton muscle atrophy.Methods1.Construction of sciatic nerve injury model in rats,then the rats were randomly divided into 2 groups,injury group and injury+EA group.The injury+EA group were treated with electroacupuncture.2.The recovery time of the claw reflection and the spread between the first and fifth toes(TS)of the 2 groups was measured and recorded before and after electroacupuncture therapy in order to evaluate the electroacupuncture therapy on the recovery of motor function after sciatic nerve injury in rats.3.The Somatosensory Evoked Potential(SEP)and Motor Evoked Potential(MEP)of the 2 groups induced by evoked potentiometer were recorded before and after electroacupuncture therapy,comparing the variations of waveform to evaluate the electroacupuncture therapy on the recovery of sensory and motor function after sciatic nerve injury in rats.4.The gastrocnemius wet weight was calculated at 2 or 4 weeks after the electroacupuncture therapy,then to calculate the decreased ratio of gastrocnemius wet weight and to evaluate the improvement of muscle atrophy in peripheral nerve injury denervated area by electroacupuncture therapy.5.In order to explore the mechanism of electroacupuncture therapy on the denervation of skeleton muscle atrophy,the levels of SOD and MDA in the gastrocnemius muscle of the ipsilateral were measured and the expression of Bcl-2 protein was detected by Western Blot.Results1.The expanding claw reflection was disappeared after the construction of sciatic nerve injury model,and the affected limbs appears to be ankle sagging,the toes cannot be separated,limping and shuffling with the hind limb.The expanding claw reflection was partial recovered after 4 weeks' treatment with electroacupuncture of the 2 groups,while compared with the injury group,the recovery time of the expanding claw reflection was shortened remarkable in the injury+EA group(P<0.01).2.The TS of the 2 groups was decreased after the construction of sciatic nerve injury model,and which were all partial recovered after 4 weeks' treatment with electroacupuncture,but compared with the injury group,the the average TS was longer in the injury+EA group(P<0.01).3.The evoked potentiometer was able to observe the complete waveform of SEP before the construction of sciatic nerve injury model,while the waveform of SEP was disappeared or damaged after surgery.Then we found that the damaged waveform of SEP was unrecovered in the injury group but partial recovered in the injury+EA group 2 weeks after the surgery.While 4 weeks after the surgery,the damaged waveform of SEP were all partial recovered in the 2 groups,and the recovery rate was more significance in the injury+EA group(P<0.01).4.The evoked potentiometer could observe the complete waveform of MEP before surgery,while the waveform of MEP was disappeared or damaged after surgery.Then we found that the damaged waveform of MEP were partial recovered in both groups 2 and 4 weeks after the surgery.And compared with the injury group,the recovery rate was more significance in the injury+EA group(P<0.05).5.Compared with the contralateral,the gastrocnemius wet weight were all lower in the ipsilateral after 2 weeks with electroacupuncture therapy of the 2 groups,and the decreased ratio of gastrocnemius wet weight was 22.32±4.06%in the injury group and 12.84±3.61%in the injury+EA group,the differences between which were statistically significant(P<0.01).6.Compared with the injury group,the activity of SOD in the gastrocnemius muscle of the injury+EA group was significantly higher than that of the injury group(P<0.01),and the content of MDA was significantly lower than that of the injury group(P<0.05).7.We found that the expression of Bcl-2 protein in the ipsilateral gastrocnemius of the injury group was lower than the contralateral gastrocnemius(P<0.05),while the expression of Bcl-2 protein in the injury+EA group was significantly higher than that of the injury group(P<0.01)when we detected the expression of Bcl-2 protein in the gastrocnemius muscle tissues by Western Blot.Conclusion1.Electroacupuncture can shorten the recovery time of claw reflection and promote the recovery of the distance between toes,the waveform of SEP and MEP,so as to accelerate the function repair of the sensory and motor in peripheral nerve injury and play the role of nerve regeneration in rats.2.Electroacupuncture can reduce the decreased raio of the gastrocnemius wet weight in rats with sciatic nerve injury,induce muscle contraction,improve local circulation and delay muscle atrophy.3.Electroacupuncture can elevate the expression of SOD which can antioxidant free radicals and inhibit the release of MDA which was the end product of oxygen radical,thus reducing the damage of oxygen radicals to the skeleton muscle.Meanwhile,electroacupuncture therapy can promote the expression of Bcl-2 protein which with the effects of anti-apoptotic,and inhibit the apoptosis of the denervation of skeleton muscle cells,then prevent the atrophy of skeleton muscle. |
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