Liao Zhi-Yin, Zhao Ke-Xiang, Xiao Qian
Department of Geriatrics, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China. E-mail:
Nan Fang Yi Ke Da Xue Xue Bao. 2017 Oct 20;37(10):1405-1409. doi: 10.3969/j.issn.1673-4254.2017.10.21.
To observe the effect of resveratrol on muscle mass, forelimb grip strength, myofibril structure and AMPK/sirt1 pathway in skeletal muscles of aged rats.
Twenty aged (25 months old) SD rats were randomly divided into aged control group and resveratrol treatment group (10 in each group) with 10 young (6 months old) rats served as the young control group. In resveratrol treatment group, the rats were treated with resveratrol (mixed in chow) for 6 weeks. After the treatment, the mass of the gastrocnemius was measured and the sarcopenia index (SI) was calculated as the gastrocnemius mass (mg) to body weight (g) ratio. The forelimb grip strength of the rats was measured using a electronic grip strength meter, and the lengths of the sarcomere, I-band, A-band and H-zone of the myofibrils were determined by transmission electron microscopy.
Compared with the young rats, the aged control rats had significantly lower SI of the gastrocnemius (P<0.05) and grip strength (P<0.05) with increased lengths of the sarcomere, A-band, I-band and H-zone (P<0.05) and lowered expressions of AMPK, P-AMPK, and sirt1 protein (P<0.05). Resveratrol treatment of the aged rats significantly increased the forelimb grip strength, reduced the lengths of sarcomere length, I-band and H-zone (P<0.05) and increased, P-AMPK, sirt1 protein expressions (P<0.05) without significantly affecting the SI (P>0.05) or the A-band length (P>0.05).
Resveratrol does not improve the muscle mass but can increase the forelimb grip strength in aged rats possibly by activating AMPK/sirt1 pathway to improve the ultrastructure of the myofibrils.
观察白藜芦醇对老年大鼠骨骼肌肌肉量、前肢握力、肌原纤维结构及AMPK/sirt1信号通路的影响。
将20只老年（25月龄）SD大鼠随机分为老年对照组和白藜芦醇治疗组（每组10只），另设10只青年（6月龄）大鼠作为青年对照组。白藜芦醇治疗组大鼠给予白藜芦醇（混入饲料中）治疗6周。治疗后，测量腓肠肌质量并计算肌少症指数（SI），即腓肠肌质量（mg）与体重（g）之比。使用电子握力计测量大鼠前肢握力，通过透射电子显微镜测定肌原纤维的肌节、I带、A带和H区长度。
与青年大鼠相比，老年对照大鼠腓肠肌的SI显著降低（P<0.05），握力显著降低（P<0.05），肌节、A带、I带和H区长度增加（P<0.05），AMPK、P-AMPK和sirt1蛋白表达降低（P<0.05）。白藜芦醇治疗老年大鼠可显著增加前肢握力，缩短肌节长度、I带和H区长度（P<0.05），增加P-AMPK、sirt1蛋白表达（P<0.05），但对SI（P>0.05）和A带长度（P>0.05）无显著影响。
白藜芦醇不能改善老年大鼠的肌肉量，但可能通过激活AMPK/sirt1信号通路改善肌原纤维超微结构，从而增加老年大鼠的前肢握力。
