Zhao Dan-Dan, Tang Cheng-Lin, Huang Si-Qin, Luo Ao, Zhang An-Ning, Guo Quan-Hu, Cao Jing, Gao Rui-Qi
College of Traditional Chinese Medicine of Chongqing Medical University, Chongqing 400016, China; Chongqing Key Laboratory of Traditional Chinese Medicine for Prevention and Cure of Metabolic Diseases, Chongqing 400016, China.
Zhen Ci Yan Jiu. 2017 Dec 25;42(6):489-95. doi: 10.13702/j.1000-0607.2017.06.004.
To explore the effects and mechanism of different duration electroacupuncture (EA) on adaptive hypertrophy of gastrocnemius and the expressions of proliferation cell nuclear antigen (PCNA), paired box transcription factor 7 (Pax 7), myogenic differentiation antigen (MyoD 1), myogenin (MyoG), myosin heavy chain-Ⅰ(Myh 7), transforming growth factor-β 1 (TGF-β 1), Smad 3 in rats.
Twenty-four SD adult male rats were randomly divided into normal, two-week EA (A 2), four-week EA (A 4) and eight-week EA (A 8) groups, 6 rats in each group. Except the normal group, EA was applied at right "Zusanli" (ST 36) and "Huantiao" (GB 30) for 10 min in the other three groups, separately for 2 weeks, 4 weeks and 8 weeks, once a day, 6 times a week. The ratio of gastrocnemius wet weight was calculated after EA. The cross-sectional area and diameter of muscle fiber were measured after HE staining. The expression of PCNA protein was detected by immunofluorescence. The relative expressions of Pax 7, MyoD 1, MyoG, Myh 7, TGF-β 1 and Smad 3 mRNA were tested with real-time PCR.
The expressions of PCNA protein were obviously higher in the A 2 and A 4 groups than that in the normal group. The expression of genes in the EA intervention groups showed a trend of increasing first and then decreasing except Smad 3 mRNA. The relative expressions of Pax 7 and TGF-β 1 mRNAs reached their peaks in the A 2 group compared with those in the normal group (<0.01). The ratio of gastrocnemius wet weight, cross-sectional area and diameter of muscle fiber, and the relative expressions of MyoD 1, MyoG, Myh 7 mRNAs reached their peaks in the A 4 group (<0.01), while the relative expression of Smad 3 mRNA showed a trend of decreasing first and then increasing and reached its bottom at the 4 week (<0.01).
EA at "Zusanli" (ST 36) and "Huantiao" (GB 30) may induce adaptive hypertrophy of gastrocnemius in rats by up-regulating the expressions of Pax 7, PCNA, TGF-β 1, MyoD 1, MyoG, Myh 7 and down-regulating the expression of Smad 3, promoting the proliferation of skeletal satellite cells, myogenic differentiation, myotubes terminal differentiation, increasing the wet weight, fiber cross-sectional area and diameter of gastrocnemius.
探讨不同时长电针刺激对大鼠腓肠肌适应性肥大及增殖细胞核抗原（PCNA）、配对盒转录因子7（Pax 7）、生肌分化抗原（MyoD 1）、生肌调节因子（MyoG）、肌球蛋白重链Ⅰ（Myh 7）、转化生长因子-β 1（TGF-β 1）、Smad 3表达的影响及其机制。
将24只成年雄性SD大鼠随机分为正常组、电针2周组（A 2）、电针4周组（A 4）和电针8周组（A 8），每组6只。除正常组外，其余三组大鼠于右侧“足三里”（ST 36）和“环跳”（GB 30）穴位进行电针刺激，每次10分钟，分别持续2周、4周和8周，每天1次，每周6次。电针结束后计算腓肠肌湿重比。HE染色后测量肌纤维横截面积和直径。采用免疫荧光法检测PCNA蛋白表达。采用实时荧光定量PCR检测Pax 7、MyoD 1、MyoG、Myh 7、TGF-β 1和Smad 3 mRNA的相对表达量。
A 2组和A 4组PCNA蛋白表达明显高于正常组。除Smad 3 mRNA外，电针干预组各基因表达呈先升高后降低趋势。与正常组相比，A 2组Pax 7和TGF-β 1 mRNA相对表达量达到峰值（<0.01）。A 4组腓肠肌湿重比、肌纤维横截面积和直径以及MyoD 1、MyoG、Myh 7 mRNA相对表达量均达到峰值（<0.01），而Smad 3 mRNA相对表达量呈先降低后升高趋势，4周时达到最低值（<0.01）。
电针“足三里”（ST 36）和“环跳”（GB 30）可能通过上调Pax 7、PCNA、TGF-β 1、MyoD 1、MyoG、Myh 7表达，下调Smad 3表达，促进骨骼肌卫星细胞增殖、生肌分化、肌管终末分化，增加腓肠肌湿重、纤维横截面积和直径，从而诱导大鼠腓肠肌适应性肥大。
