Regional adaptation of collagen in skeletal muscle to repeated bouts of strenuous eccentric exercise.
Regional adaptation of collagen in skeletal muscle to repeated bouts of strenuous eccentric exercise.
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骨骼肌中胶原蛋白对反复剧烈离心运动的区域适应。
DOI：
10.1007/s00424-016-1860-3
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
N.
中科院分区：
文献类型：
--
作者：
Takagi;R.;Ogasawara;R.;Tsutaki;A.;Nakazato;K. and Ishii;N.
本研究调查了与“重复回合效应”（RBE）相关的因素的损伤区域特异性改变，即，当第一轮离心运动产生抵抗来自第二轮相同运动的损伤时。将Wistar大鼠分为单次损伤（SI）组和重复损伤（RI）组。SI组在14周龄时，RI组在10和14周龄时，右侧腓肠肌进行一次离心收缩（ECs）。最后一次EC后，RI中受损纤维的数量低于SI。SI组内皮细胞损伤后受损纤维主要位于肌肉浅层，表达肌球蛋白重链（MHC）Ⅱ x和Ⅱ b。在第二轮EC之前，RI组的纤维类型组成显示与SI组相比，MHC IIx和IIb纤维减少，MHC IIa纤维增加。然而，大多数再生纤维显示MHC IIx或IIb表达。热休克蛋白72和总胶原含量RI组均高于SI组，但RI组仅在肌肉浅层胶原表达较SI组强。这些结果表明，在RBE中，胶原增加可能在肌肉损伤区域起着比其他因素更重要的作用。
This study investigated the injured region-specific alterations of factors related to the “repeated bout effect” (RBE), i.e., when the first bout of eccentric exercise generates resistance to injuries from the second bout of the same exercise. Wistar rats were divided into single injury (SI) and repeated injury (RI) groups. The right gastrocnemius muscle was subjected to a bout of eccentric contractions (ECs) at the age of 14 weeks in the SI group and 10 and 14 weeks in the RI group. The number of injured fibers after the last bout of ECs was lower in RI than in SI. In the SI group, injured fibers after ECs were mainly located in the superficial region of muscle and expressed myosin heavy chain (MHC) IIx and IIb. Prior to the second bout of ECs, the fiber-type composition in the RI group showed decreased MHC IIx and IIb fibers and increased MHC IIa fibers compared with those in the SI group. However, most regenerating fibers showed either MHC IIx or IIb expression. Heat shock protein 72 and total collagen contents in whole muscle were higher in the RI group than in the SI group; however, only the collagen expression in the RI group was more intense than that in the SI group in the superficial region of muscle. These findings suggest that increased collagen may play a more important role in the injured region of muscle than the other factors in RBE.