Sarcoplasmic reticulum Ca2+ pump expression in denervated skeletal muscle.
Sarcoplasmic reticulum Ca2+ pump expression in denervated skeletal muscle.
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去神经骨骼肌中肌浆网 Ca2 泵的表达。
DOI：
10.1152/ajpcell.1994.267.2.c617
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Kandarian,S
中科院分区：
文献类型：
--
作者：
Schulte,L;Peters,D;Taylor,J;Navarro,J;Kandarian,S
这项研究是为了更好地理解收缩活动如何调节骨骼肌的兴奋-收缩耦合表型。本研究分析了去神经支配对肌浆网Ca(2+)-腺苷三磷酸酶（ATPase）表达的影响，该蛋白是收缩-舒张循环的关键蛋白。在坐骨神经横断后1、4、7、14和28天，测量大鼠比目鱼肌和指长伸肌（EDL）的肌肉质量、sarco（endo）质网Ca(2+)- atp酶（SERCA）特异性异构体mRNA和蛋白表达以及与肌肉松弛相关的收缩参数。在去神经支配28天后，比目鱼肌和EDL肌的湿肌质量降至对照组的35% （P < 0.05）。Northern和Western分析显示，去神经支配的比目鱼肌中慢速Ca2+泵异构体（SERCA2a）和去神经支配的EDL肌中快速Ca2+泵异构体（SERCA1）的mRNA和蛋白表达减少，特别是在较晚的时间点。在两种肌肉类型中交替异构体的表达没有变化。抽搐收缩时间延长，张力发展速度减慢，频率-张力曲线左移与Ca2+泵密度降低一致，表明SR或去神经的ST和FT肌肉中Ca2+处理减慢。结果与先前报道的生物力学卸载引起的非负重肌肉的结果形成鲜明对比。
This study was undertaken as one approach to better understand how contractile activity regulates excitation-contraction coupling phenotype in skeletal muscle. The effects of denervation on the expression of the sarcoplasmic reticulum (SR) Ca(2+)-adenosinetriphosphatase (ATPase), a key protein of the contraction-relaxation cycle, was analyzed in fast-twitch (FT) and slow-twitch (ST) skeletal muscle. Muscle mass, mRNA, and protein expression of specific isoforms of the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) and contractile parameters related to muscle relaxation were measured in rat soleus and extensor digitorum longus (EDL) muscles at 1, 4, 7, 14, and 28 days after sciatic nerve transection. Wet muscle mass decreased to 35% of control by 28 days of denervation in both soleus and EDL muscles (P < 0.05). Northern and Western analyses showed decreases in mRNA and protein expression of the slow Ca2+ pump isoform (SERCA2a) in the denervated soleus muscle and in the fast Ca2+ pump isoform (SERCA1) in the denervated EDL muscle, particularly at later time points. There was no change in the expression of the alternate isoform in either muscle type. Prolongation of twitch contraction times, slowed rates of tension development, and leftward shifts in frequency-tension curves were consistent with the reduced Ca2+ pump density and suggested slowed Ca2+ handling in SR or denervated ST and FT muscles. The results are in marked contrast with those previously reported in non-weight-bearing muscle induced by biomechanical unloading.