低频复合生理频率电刺激对慢性低压缺氧兔颏舌肌 - 第三军医大学学报.doc

低频复合生理频率电刺激对慢性低压缺氧兔颏舌肌肌球蛋白重链表达的影响 张 妮，刘 熙，刘 刚（400038 重庆，第三军医大学西南医院呼吸内科） [摘要]目的 研究低频复合生理频率慢性电刺激对低压缺氧兔颏舌肌肌球蛋白重链（myosin heavy chain，MHC）亚型表达的影响。方法 将成年日本大白兔24 只，雌雄不拘，体质量（2.3±0.1）kg，随机分为4组（n=6）。A：正常对照组，B：慢性低压缺氧组，C：10Hz电刺激组，D：10+40Hz电刺激组。B、C、D组兔置于慢性低压缺氧环境中饲养后，分别给予C组兔颏舌肌低频（10 Hz）电刺激，D组兔颏舌肌低频复合生理频率(10+40 Hz)电刺激，B组兔不予电刺激。采用SDS-聚丙烯酰胺凝胶电泳及半定量反转录聚合酶链式反应(RT-PCR)法，分析正常对照组、慢性低压缺氧组、10Hz电刺激组及(10+40)Hz电刺激组颏舌肌MHC各亚型表达变化。结果 ①与正常对照组比较，慢性低压缺氧组颏舌肌MHCⅠ亚型比例减少[（0.69±0.07)% vs（17.48±4.00） vs（73.33±4.17） vs( 1.05±0.06)，P＜0.05)]。②与慢性低压缺氧组比较，10Hz电刺激组颏舌肌MHCⅠ亚型比例[（18.78±3.49)% vs（11.37±4.27）10+40）Hz电刺激组颏舌肌MHCⅠ亚型比例[（23.40±4.65)% vs（11.37±4.27）10+40）Hz电刺激组颏舌肌MHCⅡa亚型比例[（67.90±5.66)% vs（79.89±5.09）0Hz电刺激组颏舌肌MHCⅠ亚型mRNA表达量（0.79±0.07 vs 0.69±0.07， P＜0.05) 及（10+40）Hz电刺激组颏舌肌MHCⅠ亚型mRNA表达量（0.97±0.08 vs0.69±0.07， P＜0.05) 均增高，而MHCⅡa亚型mRNA表达量差异不显著。结论 慢性电刺激后低压缺氧兔颏舌肌MHC呈现Ⅱa 向Ⅰ型转变，即“由快向慢”转变。其中低频复合生理频率电刺激组变化的趋势更加明显。 关键词：慢性电刺激；颏舌肌； MHC亚型 Effect of electrical stimulus at a low physiological frequency on expression of myosin heavy chain in genioglossus of rabbits with chronic hypoxia Zhang Ni，Liu Xi，Liu Gang (Department of Respiratory Diseases，Third Military Medical University，Chongqing 400038，China) [Abstract] Objective To study the effect of chronic electrical stimulus at a low physiological frequency on expression of myosin heavy chain (MHC) in genioglossus of rabbits with chronic hypoxia. Methods Twenty-four adult rabbits, weighing 2.3±0.1kg, were randomized into control group (A)，hypoxia group (B)， (C), and 10+40Hz electrical stimulus group (D). Rabbits in groups C and D received electrical stimulus of genioglossus at a frequency of 10Hz and 10+40Hz, respectively, while those in group B received no electrical stimulus, after they were placed in a hypobaric hypoxia cabin, 8 h a day for 5 weeks, with free access to food and water. Expression of MHC in genioglossus of rabbits in the 4 groups was detected by SDSand semi-quantitative inverse transcription RT-PCR, respectively. Results The expression level of MHCⅠa