Human vastus lateralis and soleus muscles display divergent cellular contractile properties
Human vastus lateralis and soleus muscles display divergent cellular contractile properties
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DOI：
10.1152/ajpregu.90564.2008
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发表时间：
2008-11-01
影响因子：
2.8
通讯作者：
Trappe, Scott
中科院分区：
文献类型：
--
作者：
Luden, Nicholas;Minchev, Kiril;Trappe, Scott
本研究的目的是调查潜在的差异，在单纤维收缩生理的纤维具有相同的肌球蛋白重链亚型（MHC I和MHC IIa）来自不同的肌肉。从27名娱乐活跃的女性（31 +/- 1岁，59 +/- 1 kg）中获得股外侧肌（VL）和比目鱼肌活检。共943个单纤维（MHC I = 562; MHC IIa = 301）进行了分离和检查的直径，峰值张力（Po），缩短速度（Vo），和功率。比目鱼肌与VL肌相比，具有更大（P < 0.05）的纤维（MHC I + 18%; MHC IIa + 19%）、更高的MHC I Vo（+13%）和更高的MHC I Po（+18%）。相比之下，来自VL的纤维与比目鱼肌相比具有更高（P < 0.05）的比张力（MHC I + 18%; MHC IIa +20%）和MHC I标准化功率（+25%）。有一种趋势，MHC IIa比目鱼肌纤维具有较高的Vo [MHC IIa +13%（P = 0.058）]，而VL MHC IIa纤维显示出较高的归一化功率与比目鱼肌纤维相比的趋势[MHC IIa +33%（P = 0.079）]。没有检测到肌肉之间的绝对力量存在差异。这些数据突出了单纤维收缩功能的肌肉特异性差异，当将骨骼肌组织的观察从一个感兴趣的肌肉扩展到其他起源肌肉时，这些差异应作为考虑的科学依据。这在检查骨骼肌对身体状态（如老化、卸载和训练）的适应性时很重要。
The purpose of this study was to investigate potential differences in single-fiber contractile physiology of fibers with the same myosin heavy chain isoform (MHC I and MHC IIa) originating from different muscles. Vastus lateralis (VL) and soleus biopsies were obtained from 27 recreationally active females (31 +/- 1 yr, 59 +/- 1 kg). A total of 943 single fibers (MHC I = 562; MHC IIa = 301) were isolated and examined for diameter, peak tension ( Po), shortening velocity (Vo), and power. The soleus had larger (P < 0.05) fibers (MHC I + 18%; MHC IIa + 19%), higher MHC I Vo (+13%), and higher MHC I Po (+18%) compared with fibers from the VL. In contrast, fibers from the VL had higher (P < 0.05) specific tension (MHC I + 18%; MHC IIa +20%), and MHC I normalized power (+25%) compared with the soleus. There was a trend for MHC IIa soleus fibers to have higher Vo [MHC IIa +13% (P = 0.058)], whereas VL MHC IIa fibers showed a trend for higher normalized power compared with soleus fibers [MHC IIa +33% (P = 0.079)]. No differences in absolute power were detected between muscles. These data highlight muscle- specific differences in single- fiber contractile function that should serve as a scientific basis for consideration when extending observations of skeletal muscle tissue from one muscle of interest to other muscles of origin. This is important when examining skeletal muscle adaptation to physical states such as aging, unloading, and training.