4周悬吊大鼠比目鱼肌强直收缩力降低及其机理分析

发布时间：2019-01-01 09:48

【摘要】：目的观测尾部悬吊 4周大鼠比目鱼肌 (SOL)强直收缩力降低的动态特征 ,并探讨其可能机理。方法采用离体SOL与趾长伸肌 (EDL)灌流方法 ,测量其单次与强直收缩张力。结果尾部悬吊模拟失重 4周 ,大鼠SOL明显萎缩 ,但EDL重量保持不变。悬吊大鼠SOL单次收缩的最大张力明显降低 ,且具有明显的刺激电压依赖性 ;达到张力峰值与舒张的时间明显缩短。EDL单次收缩的最大张力虽然显著降低 ,但未见明显的刺激电压依赖性 ,时间参数亦未发生改变。悬吊大鼠SOL强直收缩的最大张力显著降低 ,且发生迅速的衰退 ,在强直收缩的第 33秒时 ,其强直收缩的张力已降低了 73%。悬吊大鼠SOL强直收缩张力的动态曲线与EDL的相似。EDL的强直收缩最大张力也显著降低 ,但衰减速率未改变。结论悬吊 4周大鼠SOL强直收缩最大张力降低且易衰退 ,前者可能与单位面积内收缩装置减少以及每一横桥产力减少相关 ;后者则可能是由于收缩与调节蛋白异构体发生转化 ,以及肌肉电兴奋性改变所导致
[Abstract]:Objective to observe the dynamic characteristics of the decrease of (SOL) contractility in soleus muscle of rats with tail suspension for 4 weeks and to explore its possible mechanism. Methods the isolated SOL and extensor digitorum longus (EDL) were perfused to measure the tension of single and tetanic contraction. Results after 4 weeks of simulated weightlessness, SOL shrank significantly, but the weight of EDL remained unchanged. The maximal tension of single contraction of SOL was significantly decreased in suspension rats, and the maximal tension was significantly dependent on the stimulation voltage. The time to reach the peak and diastole of EDL was significantly shortened, but the maximal tension of single contraction of EDL was significantly decreased, but there was no obvious voltage dependence of stimulation, and the time parameters did not change. The maximal tension of tetanic contraction of SOL in suspension rats was significantly decreased, and a rapid decline occurred. At the 33rd second of the contraction, the tension of tetanic contraction had been reduced by 73 parts. The dynamic curve of the tension of SOL was similar to that of EDL. The maximal tension of EDL also decreased significantly, but the attenuation rate did not change. Conclusion the maximal tension of SOL ankylosis in rats with 4 weeks of suspension is decreased and it is easy to decline. The former may be related to the decrease of contraction device per unit area and the reduction of productivity of each transverse bridge. The latter may be due to the transformation of contractile and regulatory protein isomers, as well as changes in muscle electrical excitability.
【作者单位】：第四军医大学航空航天生理学教研室第四军医大学航空航天生理学教研室第四军医大学航空航天生理学教研室第四军医大学航空航天生理学教研室第四军医大学航空航天生理学教研室
【基金】：高等学校骨干教师资助计划项目部分资助军队卫生科研基金重点项目 (98Z0 83 )部分资助
【分类号】：R852.22

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