Using immunohistochemistry, we investigated whether daily administration of clenbuterol (CLE; 1 mg/kg body weight per day) accelerates recovery after casted immobilization(IMM)-induced atrophy of fast-twitch plantaris and slow-twitch soleus muscles. Adult male Sprague-Dawley rats were assigned to the control (CON), casted immobilization (IMM), casted immobilization following recovery control (RCON), and casted immobilization following recovery with CLE administration (RCLE) groups. Casted immobilization and recovery periods were 9 and 14days, respectively. Rats of the CON group were subjected to the experiment simultaneously with the IMM group. Nine days of immobilization induced muscle fiber atrophy, which was greater in the soleus muscle than in the plantaris muscle. After the 2-week recovery period, the cross-sectional areas of each fiber type in both muscles were higher in the RCON group than in the IMM group. The cross-sectional areas of each fiber type in both muscles in the RCLE group were larger than those in the RCON group. The myonuclear number of each fiber type of the plantaris muscle in the RCON and RCLE groups was higher than that in the CON group. In contrast, the myonuclear number per fiber of the soleus muscle was not affected by hindlimb immobilization, reloading, and clenbuterol administration regardless of muscle fiber type. These results suggest that CLE accelerates the recovery of atrophied plantaris and soleus muscles fibers and that their mechanisms of responses to CLE in both muscles may be different during recovery period after muscle atrophy.

中文翻译：

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盐酸克伦特罗加速固定后诱导的大鼠后肢肌肉萎缩后的恢复。

使用免疫组织化学，我们调查了每天服用盐酸克伦特罗（CLE；每天1 mg / kg体重）是否在石膏固定（IMM）引起的快肌plant肌和慢肌比目鱼肌萎缩后加速恢复。将成年雄性Sprague-Dawley大鼠分为对照组（CON），石膏固定（IMM），恢复控制后石膏固定（RCON）和CLE管理（RCLE）组恢复后石膏固定。石膏固定和恢复期分别为9天和14天。CON组的大鼠与IMM组同时进行实验。固定9天会引起肌纤维萎缩，比目鱼肌比than肌更大。经过2周的恢复期后，RCON组的两种肌肉中每种纤维类型的横截面积均高于IMM组。RCLE组的两条肌肉的每种纤维类型的横截面积均大于RCON组的横截面积。RCON和RCLE组groups肌每种纤维类型的肌核数均高于CON组。相反，比目鱼肌每根纤维的肌核数不受后肢固定，再加载和克仑特罗给药的影响，而与肌肉纤维类型无关。这些结果表明，CLE促进萎缩的plant肌和比目鱼肌纤维的恢复，并且在肌肉萎缩后的恢复期间，它们对两种肌肉对CLE的反应机制可能有所不同。RCLE组的两条肌肉的每种纤维类型的横截面积均大于RCON组的横截面积。RCON和RCLE组groups肌每种纤维类型的肌核数均高于CON组。相反，比目鱼肌每根纤维的肌核数不受后肢固定，再加载和克仑特罗给药的影响，而与肌肉纤维类型无关。这些结果表明，CLE促进了萎缩的plant肌和比目鱼肌纤维的恢复，并且在肌肉萎缩后的恢复期间，它们对两种肌肉对CLE的反应机制可能有所不同。RCLE组的两只肌肉中每种纤维类型的横截面积均大于RCON组的横截面积。RCON和RCLE组groups肌每种纤维类型的肌核数均高于CON组。相反，比目鱼肌每根纤维的肌核数不受后肢固定，再加载和克仑特罗给药的影响，而与肌肉纤维类型无关。这些结果表明，CLE促进萎缩的plant肌和比目鱼肌纤维的恢复，并且在肌肉萎缩后的恢复期间，它们对两种肌肉对CLE的反应机制可能有所不同。RCON和RCLE组groups肌每种纤维类型的肌核数均高于CON组。相反，比目鱼肌每根纤维的肌核数不受后肢固定，再加载和克仑特罗给药的影响，而与肌肉纤维类型无关。这些结果表明，CLE促进了萎缩的plant肌和比目鱼肌纤维的恢复，并且在肌肉萎缩后的恢复期间，它们对两种肌肉对CLE的反应机制可能有所不同。RCON和RCLE组groups肌每种纤维类型的肌核数均高于CON组。相反，比目鱼肌每根纤维的肌核数不受后肢固定，再加载和克仑特罗给药的影响，而与肌肉纤维类型无关。这些结果表明，CLE促进萎缩的plant肌和比目鱼肌纤维的恢复，并且在肌肉萎缩后的恢复期间，它们对两种肌肉对CLE的反应机制可能有所不同。