Regulation of synthesis of fibrillar collagens in rat skeletal muscle during immobilization in shortened and lengthened positions
Regulation of synthesis of fibrillar collagens in rat skeletal muscle during immobilization in shortened and lengthened positions
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DOI：
10.1046/j.1365-201x.2001.00848.x
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发表时间：
2001-06-01
期刊：
影响因子：
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通讯作者：
Takala, TES
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文献类型：
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作者：
Ahtikoski, AM;Koskinen, SOA;Takala, TES
制动已被证明会导致肌肉萎缩和骨骼肌中总胶原合成减少。这些变化可以通过拉伸来抵消。本研究的目的是发现在缩短的末端延长的位置制动的早期影响I型和III型胶原的表达在翻译前和翻译后水平。在1，3和7天的固定在缩短和延长的位置，在比目鱼肌（SOL），腓肠肌（GM），趾长伸肌和胫骨前肌（TA）的I型和III型胶原的mRNA水平，脯氨酰4-羟化酶活性，总胶原浓度和I型和III型胶原的比例进行了分析。除TA外，所有肌肉中I型和III型胶原蛋白的mRNA水平在3-7天内均下降。在缩短GM和SOL中，I型胶原的mRNA水平低于相应的延长肌肉。脯氨酰4-羟化酶活性下降，在所有的肌肉在3-7天。在3-7天内，缩短的GM比延长的GM活性低30- 3 - 7%。总胶原蛋白浓度和比例的I型和III型胶原蛋白在7天的固定期内没有变化。目前的研究表明，制动的结果在快速下调总肌肉胶原蛋白的合成和时间和程度是大致相似的I型和III型胶原蛋白。拉伸似乎部分抵消了这些影响。固定效果和部分预防效果的拉伸在固定过程中脯氨酰4-羟化酶和纤维状胶原的基因表达下调似乎是更大的负重SOL和GM比踝关节背屈肌。
Immobilization has been shown to cause muscle atrophy and decreased total collagen synthesis in skeletal muscle. These changes can be counteracted by stretch. The purpose of this study was to find out the early effects of immobilization in shortened end lengthened positions on expression of type I and III collagen at pre- and post-translational level. The mRNA levels of type I and III collagen, prolyl 4-hydroxylase activity, total collagen concentration and the proportions of type I and III collagens were analysed in soleus (SOL), gastrocnemius (GM), extensor digitorum longus and tibialis anterior (TA) muscles during immobilization in shortened and lengthened positions for 1, 3 and 7 days. The mRNA levels for type I and III collagens decreased during 3-7 days in all muscles, except TA. In shortened GM and SOL, the mRNA level of type I collagen was lower than in the corresponding lengthened muscles. Prolyl 4-hydroxylase activity decreased in all muscles during 3-7 days. The activity in shortened GM was 30-37% lower than in the lengthened one during 3-7 days. Total collagen concentration and proportions of type I and III collagen showed no change during the 7-day immobilization period. The present study suggests that immobilization results in rapid down-regulation of total muscular collagen synthesis and that the timing and degree is roughly similar in type I and III collagens. Stretch seems to partially counteract these effects. Immobilization effect and the partially preventive effect of stretch on down-regulation of gene expression of prolyl 4-hydroxylase and fibrillar collagens during immobilization seems to be greater in weight-bearing SOL and GM than ankle joint dorsiflexors.