绿茶提取物可减轻废用期间的肌肉损失并改善肌肉功能，但在老年大鼠卸载后未能改善肌肉恢复。
Green tea extract attenuates muscle loss and improves muscle function during disuse, but fails to improve muscle recovery following unloading in aged rats.
作者信息
Alway Stephen E, Bennett Brian T, Wilson Joseph C, Sperringer Justin, Mohamed Junaith S, Edens Neile K, Pereira Suzette L
机构信息
Laboratory of Muscle Biology and Sarcopenia, Department of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia; West Virginia Center for Clinical and Translational Science Institute, Morgantown, West Virginia; Center for Cardiovascular and Respiratory Sciences, West Virginia University School of Medicine, Morgantown, West Virginia; and
Laboratory of Muscle Biology and Sarcopenia, Department of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia; Center for Cardiovascular and Respiratory Sciences, West Virginia University School of Medicine, Morgantown, West Virginia; and.
出版信息
J Appl Physiol (1985). 2015 Feb 1;118(3):319-30. doi: 10.1152/japplphysiol.00674.2014. Epub 2014 Nov 20.
In this study we tested the hypothesis that green tea extract (GTE) would improve muscle recovery after reloading following disuse. Aged (32 mo) Fischer 344 Brown Norway rats were randomly assigned to receive either 14 days of hindlimb suspension (HLS) or 14 days of HLS followed by normal ambulatory function for 14 days (recovery). Additional animals served as cage controls. The rats were given GTE (50 mg/kg body wt) or water (vehicle) by gavage 7 days before and throughout the experimental periods. Compared with vehicle treatment, GTE significantly attenuated the loss of hindlimb plantaris muscle mass (-24.8% vs. -10.7%, P < 0.05) and tetanic force (-43.7% vs. -25.9%, P <0.05) during HLS. Although GTE failed to further improve recovery of muscle function or mass compared with vehicle treatment, animals given green tea via gavage maintained the lower losses of muscle mass that were found during HLS (-25.2% vs. -16.0%, P < 0.05) and force (-45.7 vs. -34.4%, P < 0.05) after the reloading periods. In addition, compared with vehicle treatment, GTE attenuated muscle fiber cross-sectional area loss in both plantaris (-39.9% vs. -23.9%, P < 0.05) and soleus (-37.2% vs. -17.6%) muscles after HLS. This green tea-induced difference was not transient but was maintained over the reloading period for plantaris (-45.6% vs. -21.5%, P <0.05) and soleus muscle fiber cross-sectional area (-38.7% vs. -10.9%, P <0.05). GTE increased satellite cell proliferation and differentiation in plantaris and soleus muscles during recovery from HLS compared with vehicle-treated muscles and decreased oxidative stress and abundance of the Bcl-2-associated X protein (Bax), yet this did not further improve muscle recovery in reloaded muscles. These data suggest that muscle recovery following disuse in aging is complex. Although satellite cell proliferation and differentiation are critical for muscle repair to occur, green tea-induced changes in satellite cell number is by itself insufficient to improve muscle recovery following a period of atrophy in old rats.
在本研究中，我们检验了以下假设：绿茶提取物（GTE）可改善废用后再负荷情况下的肌肉恢复。将老年（32月龄）Fischer 344 布朗挪威大鼠随机分为两组，一组接受14天的后肢悬吊（HLS），另一组接受14天的HLS，随后恢复正常行走功能14天（恢复期）。另外的动物作为笼养对照。在实验期前7天及整个实验期内，通过灌胃给予大鼠GTE（50 mg/kg体重）或水（赋形剂）。与赋形剂处理相比，GTE显著减轻了HLS期间后肢比目鱼肌质量的损失（分别为-24.8%和-10.7%，P<0.05）以及强直收缩力的损失（分别为-43.7%和-25.9%，P<0.05）。尽管与赋形剂处理相比，GTE未能进一步改善肌肉功能或质量的恢复，但灌胃给予绿茶的动物在再负荷期后，肌肉质量的损失仍较低（分别为-25.2%和-16.0%，P<0.05），强直收缩力的损失也较低（分别为-45.7和-34.4%，P<0.05）。此外，与赋形剂处理相比，GTE减轻了HLS后比目鱼肌（分别为-39.9%和-23.9%，P<0.05）和比目鱼肌（分别为-37.2%和-17.6%）肌肉纤维横截面积的损失。这种绿茶诱导的差异不是短暂的，而是在再负荷期内比目鱼肌（分别为-45.6%和-21.5%，P<0.05）和比目鱼肌纤维横截面积（分别为-38.7%和-10.9%，P<0.05）得以维持。与赋形剂处理的肌肉相比，可以观察到，在从HLS恢复过程中，GTE增加了比目鱼肌和比目鱼肌中卫星细胞的增殖和分化，并降低了氧化应激以及Bcl-2相关X蛋白（Bax）的丰度，但这并未进一步改善再负荷肌肉的恢复。这些数据表明，衰老过程中废用后的肌肉恢复情况较为复杂。尽管卫星细胞的增殖和分化对于肌肉修复至关重要，但绿茶诱导的卫星细胞数量变化本身不足以改善老年大鼠萎缩期后的肌肉恢复。
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