【摘要】 目的:探讨电针对模拟失重小鼠比目鱼肌湿重、湿重体重比、形态学改变和对其胰岛素样生长因子-1(IGF-1)的m RNA及蛋白表达水平的影响。方法:将雄性C 57小鼠28只随机分为正常对照组、同步电针组、预防电针组、模型组4组,每组7只。采用尾部悬吊法建立模拟失重模型。正常对照组常规饲养28 d;模型组前14 d常规饲养,后14 d尾部悬吊造模;预防电针组前14 d电针+常规饲养,后14 d造模;同步电针组前14 d常规饲养,后14 d电针并造模。电针取穴足三里、阳陵泉,频率20~30 Hz,电流1 m A,每次15 min,观察周期均28 d。实验结束时取比目鱼肌称重,并计算比目鱼肌湿重、比目鱼肌湿重体重比,HE染色观察肌肉形态学变化;采用Western blot和Real-time PCR法检测IGF-1的表达水平。结果:(1)与正常对照组比较,模型组小鼠体重明显降低(P<0.05),其比目鱼肌肌肉湿重和湿重体重比也明显下降(P<0.05);与模型组比较,同步电针组和预防电针组在体重、比目鱼肌湿重和湿重体重比均无显著性差异。(2)各组小鼠比目鱼肌病理切片经HE染色显示,正常对照组见小鼠比目鱼肌肌纤维排列整齐,肌纤维间排列紧密,肌膜平滑,细胞核位于肌纤维周边;模型组见小鼠比目鱼肌纤维结构紊乱、松散,肌纤维间隙增加、肌纤维间分界不清,呈病灶性表现,结缔组织增生显著;同步电针组和预防电针组的肌纤维排列紊乱减轻,结缔组织增生不明显。(3)蛋白质印迹法(Western blot)和实时荧光定量聚合酶链式反应(Real-time PCR)法检测显示,模型组的IGF-1表达较正常对照组明显降低(P<0.05),同步电针组和预防电针组经干预后IGF-1表达较模型组明显增加(P<0.05),同步电针组和预防电针组比较差异不明显。结论:电针能够减缓模拟失重小鼠骨骼肌萎缩的组织形态学改变,对可能参与肌萎缩的IGF-1有一定干预作用。更多还原

【Abstract】 Objective: To investigate the effects of electroacupuncture on the ratio of wet muscle weight and wet muscular weight to body weight,morphological changes and m RNA as well as protein expression levels of insulin-like growth factor-1(IGF-1)in the soleus muscle of simulated weightless mice. Methods:Fifty-seven male C mice were randomly divided into synchronous electroacupuncture group,model group,normal control group and preventive electroacupuncture group,with 7 rats in each group. The simulated weightlessness model was established by tail suspension method. Regular feeding lasted for 28 days in normal control group. Regular feeding lasted for the first 14 days and tail suspension molding kept for the last 14 days in model group. Electroacupuncture and routine feeding lasted for the first 14 days in preventive electroacupuncture group with molding kept for the last 14 days. Routine feeding kept for the first 14 days,and electroacupuncture as well as molding kept for the last 14 days in synchronous electroacupuncture group. Zusanli and Yanglingquan were selected as the electroacupuncture points with frequency 20~30 Hz and current 1 m A. The observation period was 28 days for 15 minutes each time. At the end of the experiment,the soleus muscle was weighed,and the wet weight as well as the ratio of the wet weight to body weight of the soleus muscle was calculated. The morphology of the muscle was observed by HE staining. Western blot and Real-Time PCR were used to detect the expression level of IGF-1. Results:(1) Compared with those in the normal control group,the weight of the mice in the model group was significantly lower(P <0.05),and the wet weight as well as the ratio of the wet weight to body weight of the soleus muscle in the model group were also significantly decreased(P <0.05). Compared with those in the model group,there was no significant difference in weight of the mice,wet weight as well as the ratio of the wet weight to body weight of the soleus muscle of the synchronous electroacupuncture group and the preventive electroacupuncture group.(2) HE staining for pathological section of the soleus muscle in each group showed that the muscle fiber structure was disordered and loose with increased muscle fiber gap and unclear muscle fiber boundary,and there was focal manifestation with obvious proliferation of the connective tissue in the model group. In the normal control group,the muscle fibers in the soleus muscle were arranged neatly and closely with smooth sarcolemma and the nucleus was located in the peripheral muscle fibers. Disorganized muscle fibers in the synchronous electroacupuncture group and the preventive electroacupuncture group were alleviated with unobvious proliferation of the connective tissue.(3) The detection of western blot and real-time fluorescence quantitative polymerase chain reaction(Realtime PCR)showed that the expression of IGF-I in the model group was significantly lower than that in the normal control group(P <0.05). The expression of IGF-I in the synchronous electroacupuncture group and the preventive electroacupuncture group was significantly increased compared with that in the model group after intervention(P <0.05).There was no significant difference between the synchronous electroacupuncture group and the preventive electroacupuncture group.Conclusion:Electroacupuncture can slow down the histomorphological changes of simulated weightless skeletal muscle atrophy and have certain interventional effect on IGF-1 which may be involved in muscle atrophy.更多还原