不同频率慢性电刺激膈神经对兔膈肌骨骼肌型二氢吡啶受体_(α1)亚单位、ryanodine受体mRNA和蛋白表达的影响  

Effect of chronic electrical stimulation of phrenic nerve at different frequencies on mRNA and protein expression of skeletal DHPRα1 and RyRs in the diaphragm muscle of rabbits

作　　者：张睢扬[1] 刘刚[1] 王东林[1] 郭先健[1] 钱桂生[1] 

机构地区：[1]第三军医大学新桥医院全军呼吸内科研究所,重庆400037

出　　处：《生理学报》2004年第2期198-203,共6页Acta Physiologica Sinica

基　　金：This work was supported by a grant from the National Natural Science Foundation of China (No:39470325).

摘　　要：测定不同频率慢性电刺激(chronic electrical stimulation,CES)膈神经5周后对兔膈肌钙释放单位中骨骼肌型二氢吡啶受体(DHPR)α1亚单位和ryanodine受体(RyrRs)的mRNA和蛋白表达水平的影响,探讨CES后兔膈肌钙释放单位结构组成的变化和可能的临床应用价值。封闭群日本大耳白兔30只,随机分为正常对照组、10、20、50和100 Hz,每组6只;以10和20 Hz为慢性低频电刺激组,50和100 Hz为慢性高频电刺激组。CES参数为波宽0.2 ms 3-6个波/次,45次/min,电压10-20 V。刺激时间2×2 h/日,每周刺激6 d,连续刺激5周。分别采用RT-PCR和免疫组织化学法测定兔膈肌骨骼肌型DHPRα1-亚单位和RyR1、RyR2和RyR3的mRNA和蛋白表达。结果显示:与对照组比较,慢性低频电刺激10和20 Hz组骨骼肌型DHPRα1-RyR2的mRNA和蛋白表达明显降低(P<0.01),有低度的RyR2mRNA的表达出现;慢性高频电刺激50和100 Hz组骨骼肌型DHPRα1-RvR1的mRNA和蛋白表达明显升高(P<0.01),未检测到RyR2mRNA的阳性表达。本实验提示慢性低频电刺激膈神经5周后,膈肌质膜上DHPR与RyRs之间的信号转导方式已从变构耦联为主转变为以Ca2+诱导Ca2+释放耦联为主。The mRNA and protein expression of skeletal dihydropyridine receptor isoform alpha, subunit (DHPRα1) and ryanodine receptor1-3 (RyR1-3) during chronic electrical stimulation (CES) of phrenic nerve have rarely been explored. In the present study, we explored the signal translation mode of calcium release unit in diaphragm muscle of rabbits after CES. Thirty rabbits were used and randomly divided into the normal, 10, 20, 50 and 100 Hz groups. Phrenic nerve was continuously (5 weeks, 2×2 h/d) stimulated at 10, 20, 50 and 100 Hz respectively (impulse width 0.2 ms, 3-6 waves/time, 45 times/min,10-20 V). Reverse transcription PCR and immunohistochemical methods were employed. The results showed that mRNA and protein expressions of DHPRα1 and RyR1 in 10 and 20 Hz groups were more significantly lower than those in the control group (P<0.01), but mRNA and protein expressions of DHPRα1 and RyR1 were significantly higher in 50 and 100 Hz groups than those in the control group (P<0.01); a lower level of mRNA expression of RyR2 was found in 10 and 20 Hz groups. It is suggested that the calcium release unit and the signal transduction mode between DHPR and RyRs were altered from conformational changes of linked proteins to Ca2+-induced Ca2+ release (CICR) in the diaphragmatic muscle of rabbits after chronic low-frequency electrical stimulation of nhrenic nerve for 5 weeks.

关 键 词：细胞生理 慢性电刺激 RT-FCR 膈肌 二氢吡啶受体α1 RYANODINE受体 

分 类 号：R338[医药卫生—人体生理学]