Department of Health and Physical Education, Aichi University of Education, Kariya, Japan.
Obata Elementary School, Nagoya, Japan.
Acta Histochem. 2020 Jan;122(1):151453. doi: 10.1016/j.acthis.2019.151453. Epub 2019 Nov 21.
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.
我们通过免疫组织化学方法研究了每天给予克仑特罗（CLE；1mg/kg 体重/天）是否会加速快肌比目鱼肌和慢肌跖肌在固定（IMM）诱导萎缩后的恢复。成年雄性 Sprague-Dawley 大鼠被分为对照组（CON）、固定组（IMM）、固定后恢复期对照组（RCON）和固定后恢复期给予 CLE 组（RCLE）。固定和恢复期分别为 9 和 14 天。CON 组大鼠与 IMM 组同时进行实验。9 天的固定导致肌肉纤维萎缩，比目鱼肌比跖肌更为严重。2 周恢复期后，RCON 组比 IMM 组的两种肌肉中各纤维类型的横截面积更高。RCLE 组的两种肌肉中各纤维类型的横截面积大于 RCON 组。RCON 和 RCLE 组比目鱼肌中每种纤维类型的肌核数高于 CON 组。相比之下，跖肌中每条纤维的肌核数不受后肢固定、再负荷和克仑特罗给药的影响，无论肌肉纤维类型如何。这些结果表明，CLE 加速了萎缩的比目鱼肌和跖肌纤维的恢复，并且在肌肉萎缩后的恢复期，CLE 对两种肌肉中它们的反应机制可能不同。
