Unilateral lower limb suspension does not mimic bed rest or spaceflight effects on human muscle fiber function.
Unilateral lower limb suspension does not mimic bed rest or spaceflight effects on human muscle fiber function.
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单侧下肢悬吊不会模仿卧床休息或太空飞行对人体肌肉纤维功能的影响。
DOI：
10.1152/japplphysiol.01245.2001
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发表时间：
2002
影响因子：
3.3
通讯作者：
R. Fitts
中科院分区：
文献类型：
--
作者：
J. Widrick;S. Trappe;J. Romatowski;D. Riley;D. Costill;R. Fitts
我们使用钙离子激活的皮肤肌纤维来检验单侧小腿悬吊（ULLS）改变肌肉收缩的跨桥机制的假设。在ULLS前、ULLS 12天后立即（0 h后）和reamestion 6 h后（6 h后）从8名受试者中获得比目鱼肌和腓肠肌活检。表达I型肌球蛋白重链（MHC）的0 h后比目鱼肌纤维的直径、绝对和特定峰值Ca2+激活力、无负荷缩短速度以及绝对和归一化峰值功率均显著降低。从腓肠肌获得的纤维受ULLS的影响较小，特别是表达快速MHC亚型的纤维。后6小时比目鱼肌纤维产生的绝对和特定的峰值力比后0小时的纤维，这表明后ULLS诱导细胞损伤reambraction。像卧床休息和太空飞行，ULLS主要影响比目鱼肌腓肠肌纤维。然而，在这些其他模型相比，慢比目鱼肌纤维后ULLS表现出减少卸载缩短速度和更大的减少比力。
We used Ca2+-activated skinned muscle fibers to test the hypothesis that unilateral lower leg suspension (ULLS) alters cross-bridge mechanisms of muscle contraction. Soleus and gastrocnemius biopsies were obtained from eight subjects before ULLS, immediately after 12 days of ULLS (post-0 h), and after 6 h of reambulation (post-6 h). Post-0 h soleus fibers expressing type I myosin heavy chain (MHC) showed significant reductions in diameter, absolute and specific peak Ca2+-activated force, unloaded shortening velocity, and absolute and normalized peak power. Fibers obtained from the gastrocnemius were less affected by ULLS, particularly fibers expressing fast MHC isoforms. Post-6 h soleus fibers produced less absolute and specific peak force than did post-0 h fibers, suggesting that reambulation after ULLS induced cell damage. Like bed rest and spaceflight, ULLS primarily affects soleus over gastrocnemius fibers. However, in contrast to these other models, slow soleus fibers obtained after ULLS showed a decrease in unloaded shortening velocity and a greater reduction in specific force.
肌球蛋白亚基和运动功能减退大鼠肌肉单纤维的收缩特性。
DOI：
10.1152/jappl.1987.63.6.2293
发表时间：
1987
期刊：
Journal of applied physiology (Bethesda, Md. : 1985)
影响因子：
--
作者：
Reiser,PJ;Kasper,CE;Moss,RL
通讯作者：
Moss,RL
影响因子：
3.3
作者：
Riley, DA;Bain, JLW;Costill, DL
通讯作者：
Costill, DL