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。方法成年日本大白兔24只,雌雄不拘,体质量(2.3±0.1)kg,按随机数字表法分为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(10Hz)电刺激,D组兔颏舌肌低频复合生理频率(10+40Hz)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4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)%,P<0.05],MHCⅡa亚型比例增加[(79.89±5.09)%vs(73.33±4.17)%,P<0.05];MHCⅠ亚型mRNA表达量下降[(0.69±0.07)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)%,P<0.05]及10+40Hz电刺激组颏舌肌MHCⅠ亚型比例[(23.40±4.65)%vs(11.37±4.27)%,P<0.05]均增加,而10+40Hz电刺激组颏舌肌MHCⅡa亚型比例[(67.90±5.66)%vs(79.89±5.09)%,P<0.05]减少;与慢性低压缺氧组比较,10Hz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+40Hz电刺激组颏舌肌MHCⅠ亚型mRNA表达量[(0.97±0.08)vs(0.69±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。
Objective To study the effect of chronic electrical stimulus at a low physiological frequency on the 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）,chronic hypoxia group （B）,10 Hz electrical stimulus group （C）,and 10＋40 Hz electrical stimulus group （D）.Rabbits in groups C and D received electrical stimulus of genioglossus at a frequency of 10 Hz and 10＋40 Hz,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 SDS-PAGE and semi-quantitative inverse transcription RT-PCR,respectively.Results The expression level of MHCⅠand MHCⅠmRNA was significantly lower while that of MHCⅡa was significantly higher in group B than in group A [（0.69±0.07）% vs （17.48±4.00）%,（0.69±0.07）% vs （1.05±0.06）%,and （79.89±5.09）% vs （73.33±4.17）%,P0.05].The expression level of MHCⅠwas significantly higher in groups C and D than in group B [（18.78±3.49）% vs （11.37±4.27）%,and （79.89±5.09）% vs （73.33±4.17）%,P0.05],while that of MHCⅡa was significantly lower in groups C and D than in group B [（67.90±5.66）% vs （79.89±5.09）%,（79.89±5.09）% vs （73.33±4.17）%,P0.05].The expression level of MHC I mRNA was significantly higher in groups C and D than in group B [（0.79±0.07）% vs （0.69±0.07）%,（0.97±0.08）% vs （0.69±0.07）%,P0.05].No significant difference was found in expression of MHCⅡa mRNA between groups C,D and B.Conclusion MHCⅡa in genioglossus of rabbits with chronic hypoxia is transformed to MHC I,namely from rapid to slow transformation,after chronic electrical stimulus,especially at a low physiological frequency.
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2010年第13期1403-1407,共5页
Journal of Third Military Medical University
基金
重庆市科技攻关资助项目(CSTC2005AC5060)
第三军医大学第一附属医院临床研究专项基金(SW2004009)~~
关键词
慢性电刺激
颏舌肌
MHC亚型
chronic electrical stimulus
genioglossus
subtypes of myosin heavy chain
