苏艳红, 宿哲, 张凯, 袁乾坤, 刘强, 吕申, 王昭辉, 邹伟
辽宁师范大学体育学院，大连 116029；大连医科大学附属第二医院分子生物学实验室，大连 116029；辽宁师范大学生命科学学院，大连 116029
本文旨在研究两种运动方式和制动状态下大鼠腓肠肌内p-Akt/MuRF1/FoxO1的蛋白表达变化，以揭示运动员不同的训练方式和停训状态下肌形态学改变的分子机制。Sprague Dawley (SD)大鼠随机分成对照组、耐力训练组、后肢悬垂组和离心训练组。耐力训练组接受跑台训练，悬吊组接受后肢悬垂，离心训练组接受坡度−16º的跑台训练。各组大鼠取腓肠肌，称取其重量，HE法测定骨骼肌细胞横截面积；免疫组化法测定p-Akt蛋白表达；免疫印迹法测定MuRF1、FoxO1的蛋白表达。结果显示，相对对照组，耐力训练组腓肠肌重量和细胞横截面积无显著变化，而离心训练组和后肢悬垂组显著降低；耐力训练组和离心训练组腓肠肌p-Akt蛋白表达显著增加，后肢悬垂组无明显变化。与对照组相比，耐力训练组MuRF1蛋白表达无明显变化，而离心训练组和后肢悬垂组则显著升高；耐力训练组FoxO1蛋白表达显著降低，而离心训练组与后肢悬垂组则显著升高。以上结果表明，增加活动的运动方式(耐力和离心训练)激活了Akt表达，但没有引起肌肉重量的增加；相反，离心训练和后肢悬垂均显著增加了MuRF1和FoxO1的蛋白表达，导致肌肉萎缩，提示MuRF1和FoxO1是造成肌肉萎缩的主要决定因素。
[The changes of p-Akt/MuRF1/FoxO1 proteins expressions in the conditions of training and immobilization in rats’ gastrocnemius muscle.] [Article in Chinese]
SU Yan-Hong, SU Zhe, ZHANG Kai, YUAN Qian-Kun, LIU Qiang, LV Shen, WANG Zhao-Hui, ZOU Wei
Physical Education College of Liaoning Normal University, Dalian 116029, China； Molecular Biology Lab, the Second Hospital of Dalian Medical University, Dalian 116029, China； College of Life Science of Liaoning Normal University, Dalian 116029, China
This study was aimed to investigate the changes of muscle protein synthesis and degradation under different movement conditions, so as to provide theoretical basis for muscle atrophy mechanism. Sprague Dawley (SD) rats were randomly divided into control, endurance training (treadmill training), hind limb overhanging and eccentric training (treadmill training, angle −16º) groups. The gastrocnemius muscles of rats were taken and weighed. The muscle was sectioned, and HE staining was employed to determine the cell’s cross-sectional area. Protein expression of p-Akt was measured by immunohistochemistry; and the expressions of MuRF1 and FoxO1 were determined by Western blot. The results showed that, compared with control group, hind limb overhanging and eccentric training groups exhibited decreased muscle weight and cross-sectional area, but endurance training group did not show any changes. The expressions of p-Akt in endurance and eccentric training groups, not in hind limb overhanging group, were significantly higher than that in control group. Compared with that of control, MuRF1 protein remained unchanged in endurance training groups, but was increased in eccentric training and hind limb overhanging groups; FoxO1 protein was decreased in endurance training group, but was increased in eccentric training and hind limb overhanging groups. These results indicate that movement (endurance and eccentric training) can activate Akt expression, but does not increase muscle weight, whereas eccentric training and hind limb overhanging can increase the expressions of MuRF1 and FoxO1, and induce amyotrophy, suggesting MuRF1 and FoxO1 are major determinant factors in muscle atrophy.
通讯作者：吕申,邹伟 E-mail: firstname.lastname@example.org,email@example.com
苏艳红, 宿哲, 张凯, 袁乾坤, 刘强, 吕申, 王昭辉, 邹伟. 运动和制动大鼠腓肠肌内p-Akt/MuRF1/FoxO1的蛋白表达变化[J]. 生理学报 2014; 66 (5): 589-596.
SU Yan-Hong, SU Zhe, ZHANG Kai, YUAN Qian-Kun, LIU Qiang, LV Shen, WANG Zhao-Hui, ZOU Wei. [The changes of p-Akt/MuRF1/FoxO1 proteins expressions in the conditions of training and immobilization in rats’ gastrocnemius muscle.] [Article in Chinese]. Acta Physiol Sin 2014; 66 (5): 589-596 (in Chinese with English abstract).