电针对腓肠肌急性钝挫伤大鼠肌肉弹性及生肌调节因子表达的影响

Effect of electroacupuncture on tissue elasticity and expression of muscular MyoD and myogenin in rats with acute gastrocnemius contusion

目的:观察电针"阿是穴"与"昆仑"对大鼠腓肠肌急性钝挫伤后腓肠肌肌肉弹性以及生肌调节因子表达的影响,探讨局部取穴与循经取穴在软组织创伤中的作用。方法:将SD大鼠随机分为空白组(5只),模型组(15只),阿是穴组(15只)和昆仑穴组(15只)。采用自制打击器建立腓肠肌钝挫伤大鼠模型。在损伤24 h后,阿是穴组取"阿是穴"进行1次电针治疗,昆仑穴组取"昆仑"进行1次电针治疗。通过剪切波弹性成像技术检测损伤前、损伤后3 h腓肠肌杨氏模量的最大值(Emax);在损伤后3、5、7 d观察腓肠肌的Emax,HE染色法观察腓肠肌病理形态,免疫组织化学法检测腓肠肌成肌分化因子(MyoD)、肌细胞生成素(MyoG)的表达。结果:模型组大鼠腓肠肌Emax在损伤后3 h、3 d、5 d、7 d均高于损伤前的正常值(P<0.05);损伤后3 d,阿是穴组Emax明显高于模型组和昆仑穴组(P<0.05);损伤后7 d,阿是穴组Emax明显低于模型组(P<0.05)。空白组大鼠有少量表达MyoD、MyoG的阳性细胞,模型组MyoD、MyoG阳性细胞数在损伤后7 d仍高于空白组(P<0.05),在损伤后3、5 d,阿是穴组MyoD、MyoG阳性细胞数明显高于模型组(P<0.05),在损伤后7 d,阿是穴组MyoG阳性细胞数明显高于模型组(P<0.05),在损伤后5 d,昆仑穴组MyoG阳性细胞数明显高于模型组(P<0.05);在损伤后3、5 d,阿是穴组MyoD阳性细胞数明显高于昆仑穴组(P<0.05)。结论:电针"阿是穴""昆仑"穴均能上调大鼠腓肠肌钝挫伤后MyoD、MyoG的表达。其中,"阿是穴"的作用更显著,并且更有利于损伤后肌肉组织弹性的恢复。

Objective To observe the effect of electroacupuncture(EA) at "Ashi" acupoint and "Kunlun"(BL60) on elastic modulus, histopathological changes and expression of myogenic regulatory factors in gastrocnemius(GM) contusion rats, so as to explore the therapeutic effect of local acupoint selection and acupoint selection along channel. Methods Male SD rats were randomly divided into blank control(n=5), model(n=15), Ashi-point(n=15) and BL60(n=15) groups. The acute GM contusion model was established by striking(free falling) the GM with a homemade hitter. EA(0.5 to 1.0 mA, 2 Hz/10 Hz) was applied to Ashi-point(local focus) and BL60 for 30 min 24 h after muscle injury. The elasticity maximum(Emax) of gastrocnemius muscle was measured by using an ultrasonic device. Histopathological changes were observed after H.E. stain, and the number of Myogenic differentiation(MyoD)-and Myogenin(MyoG)-positive cells was detected by using immunohistochemistry.Results After mdeling, the Emax value of GM was significantly increased from the 3rd h to 7th day in comparison with pre-injury of muscle(P<0.05), and was markedly increased on the 3rd day and obviously lower on day 7 in the Ashi-point group than in the model group(P<0.05). The numbers of MyoD-and MyoG-positive cells of GM were significantly increased on day 7 in the model group than in the blank control group(P<0.05), and both further increased in Ashi-point on day 3 and 5, and MyoG-positive cells further increased in BL60 group on day 5 and in Ashi-point group on day 7 relevant to the model group(P<0.05). The therapeutic effect of EA-Ashi-point was apparently superior to that of BL60 in up-regulating Emax on day 3 and in up-regulating the number of MyoD-positive cells on day 3 and 5(P<0.05). H.E. stain showed disordered arrangement of muscle fibers, infiltration of inflammatory cells, increase of intercellular space, and edema on day 3 after modeling(which was milder in the Ashi-point group);and gradual fusion and thickening of new born muscle fibers with obvious connective tissue hyperplasia converged to the lesioned region on day 7 in the model group(convergence of new born muscle cells to the lesion region in both EA groups, and more complete tissues in the Ashi-point group). Conclusion EA of Ashi-point and BL60 can up-regulate the expression of myogenic regulatory factors MyoD and MyoG of GM tissue in GM contusion rats, which may contribute to its function in promoting recovery of muscle elasticity. The role of EA-Ashi-point is superior to that of EA-BL60.