| Objective:The reparation and the reconstruction of peripheral nerve defect which was made by various reason is a problem in the area of peripheral nerve. Following the development of microsurgery,more and more technic is mastered by the resident,but the function of the denervated muscle is not satisfactory.The reason is various and the prevention of the denervated muscle atrophy is always the difficult problem of microsurgery.A model of denervated gastrocnemius muscle was established,the electromyogram the muscle wet weight diameter and cross section area of myocyte was measured after the TENS to research the effect of TENS on preventing denervated muscle atrophy. Methods:Twenty New Zealand rabbits(1.5-2.0kg) offered by hebei medical university was used in the experiment .The animals were distributed by weight stochastically to group A(1.75±0.08kg)TENS the next day after operation ; group B(1.82±0.10kg)TENS two week after operation;group C(1.74±0.10kg) TENS four week after operation and group D(1.78±0.06kg)not TENS.Rabbits were binded on the operating-table anesthetized by 0.5Lidocaine 6-8ml kg-1.A longitudinal incision was made on the left crus ,sciatic nerve was exposed and the tibial nerve was cut 2cm up the knee joint.Then the tibial nerve cut was turned 180°and sutured to the gastrocnemius and biceps femoris to prevent the natural regeneration before closed the incision.By DXZ-1treatment machine,TENS was respectively operated to the left crus the day after operation,2 week after operation 4week after operation .Pulse frequency was 10ms pulse extent was 2ms the peak of the electric current was 8-10mA frequency was 2-5Hz.The diameter of rotundity electrode was 1cm.The anode was placed on the pelvis between the ischial tuberosity and femur trochanter,the cathode was placed on the gastrocnemius.The two electrodes packed by 4-6layer gauze were soaked and placed on the skin.The same part stimulated by 4-5mA before operation,gastrocnemius of the rabbit contracts obviously without restlessness and skin adustum.The animals was stimulated once a day,30minutes one time.Electromyogram was done 6 weeks after operation,then,the materials drawed from gastrocnemius was observed under light microscopes and electron microscopes. Results:The wet weight diameter and cross sector of the denervated muscle can be obviously effected obviously.This experiment shows that the numeral of wet weight diameter and cross sector of the denervated muscle of the group.TENS the next day is higher than the group TENS 2weeks after the operation,higher than the group TENS 4 weeks after the operation and higher than the group without TENS.The difference is notable in the statistics (p<0.01).The numeral ofthe group TENS 2 weeks after the operation is higher than the group TENS 4weeks after the operation and the group without TENS.The difference is also notable in the statistics(p<0.05).But the numeral of the group TENS 4 weeks after the operation is not different with the group without TENS in the statistics(p>0.05).The influence of fibrillation potential of the denervated muscle of the four groups is not notable in the statistics(p>0.05) .But the difference is notable in the morphology.The result of the group TENS next day after operation and the group TENS 2weeks after the operation shows that in the HE staining:muscle fiber arranges orderly the clearance between the muscle fiber widens. Body cell of some muscle fiber engorges,chromatosis of the endochylema is symmetrical.Special staining(MASSON staining): the collagen fiber in the blank of the muscle fiber in the group TENS the next day after operation is not obviously.Hyperplasia of few collagenfiber in the blank of muscle fiber and muscle bundle of the group TENS 2 weeks after operation can be found. Immunohistochemistry staining:in the group TENS the next day and 2weeks after operation,the masc-grains in the endochylema is symmetrical coloration is deeper,transverse striation of some muscle fiber can be seen clearly.But, in the group TENS 4weeks after the operation and the group without TENS in the HE staining:muscle fiber arranges derangement,the blank among the muscle fiber widens obviously.The phenomena in the MASSON staining: hyperplasia of collagen fiber can be found here and...
|
PDF Full Text Request