耐力运动、抗阻运动对衰老小鼠内质网应激介导的骨骼肌细胞凋亡的干预作用

耐力运动、抗阻运动对衰老小鼠内质网应激介导的骨骼肌细胞凋亡的干预作用 耐力运动、抗阻运动对衰老小鼠内质网应激介导的骨骼 肌细胞凋亡的干预作用 论 文 摘 要 目前,人口老龄化已经成为全球各国家和地区亟需面对和解决的问。人口 老龄化对人类生活的各个方面都会产生深远的影响,其中,关于老年个体的医疗 保障和护理力度问题尤为突出。如何让老年个体享受高质量的生活水平已成为各 方领域密切关注并着手解决的课题。老年个体维持身体健康的过程就是和身体诸 多组织和器官的结构与机能上出现的衰退抗争的过程,其中以对抗骨骼肌的衰减 尤为重要。根据大量的流行病学调查表明,伴随个体衰老过程中骨骼肌的衰减严 重威胁着老年个体的身心健康。随着年龄的增长,老年个体不可避免的出现骨骼 肌肌肉质量、体积以及肌肉力量下降,造成老年人活动能力出现不同程度的丧失, 使得老年个体无法最大程度享受高水平的生活质量,严重时更会影响老年个 体的 基本身体活动水平,使得老年个体跌倒、骨折、发生各种意外的可能性增加,从 而给社会和家庭带来巨大的心理和经济负担。美国塔夫茨大学的 Irwin Rosenberg教授于1988年提出了Sarcopenia 这一概念,定义为一种随增龄而发 生的骨骼肌退行性病理现象,表现为骨骼肌肌肉质量、体积及肌肉力量下降。因 此研究并解决老年个体骨骼肌衰减问题,对于改善老年人健康水平,减轻社会经 济负担具有重要意义。 近年来各方研究结果显示,Sarcopenia 的发生发展与细胞凋亡密切相关,目 前已知有三条主要的介导细胞凋亡的信号传导通路:线粒体介导的细胞凋亡信号 通路;死亡受体因子介导的细胞凋亡信号通路以及内质网应激介导的细胞凋亡信 号通路。线粒体损伤途径内源性途径和死亡受体活化途径外源性途径是介导 细胞凋亡的两条经典途径,内质网应激启动的细胞凋亡途径是近几年才发现的一 种新的细胞凋亡途径。因此内质网应激介导的细胞凋亡信号通路在 Sarcopenia发 生发展过程中作用的阐明及围绕运动对其影响的探讨,将有助于我们了解伴 随 Sarcopenia发生的细胞凋亡机制,以期通过制定运动干预的方式来预防或者延缓 Sarcopenia给老年人带来的影响。 本文通过观察长期与短期耐力运动与抗阻运动对 C57 小鼠股四头肌横截面 积的影响以及对股四头肌内 GADD153/CHOP、ASK1/JNK及 Caspase-12 mRNA 表达的影响,旨在研究不同运动方式对内质网应激介导的细胞凋亡的干预作用。 同时为选择延缓骨骼肌衰减的运动处方提供可行性的和科学的理论依据。 实验方法:本实验选取了 34只 C57雄性小鼠作为研究对象,随机分为终身耐力运动组 (LE)、终身抗阻运动组(LR)、老年耐力运动组(OE)、老年抗阻运动组(OR)、 老年安静对照组(OC)及青年安静对照组(YC)。研究样本采用跑台作为耐力 运动模式,负重爬梯作为抗阻运动模式。终身运动组的训练时间为 19个月,老 年运动组的训练时间为 4个月,安静对照组不参与训练。训练过程结束后采用 HE染色观察小鼠股四头肌横截面积及肌纤维密度,并用 RT-PCR仪器检测小鼠 股四头肌内 GADD153/CHOP、ASK1/JNK及 Caspase-12 mRNA表达量,并进行 数据整理分析。 实验结果: 1、 经过光镜观察,对比各组样本股四头肌的横截面积与骨骼肌纤维的密度发 现,终身抗阻运动组与老年抗阻运动组骨骼肌的构型与其它各组相比保持的最为 完好,与老年对照组相比,终身耐力运动组和老年耐力运动组的股四头肌横截面 积要大于老年对照组,且骨骼肌纤维的分布与老年对照组相比也更为紧凑。青年 对照组由于正处于青壮年,未发生骨骼肌衰减的迹象,故骨骼肌的构型未见异常。 2、 在各运动组与老年对照组股四头肌内GADD153/CHOP mRNA相对表达量的比较 中,老年对照组股四头肌内GADD153/CHOP mRNA相对表达量明显高于各运动组, 并且有显著性的差异(P0.05)。老年耐力运动组、老年抗阻运动组与终身耐力 运动组相比无显著性差异(P0.05)。终身耐力运动组GADD153/CHOP mRNA表达量 最低。在各运动组与青年对照组股四头肌内GADD153/CHOP mRNA表达量的比较中, 青年对照组股四头肌内GADD153/CHOP mRNA相对表达量明显高于各运动组, 并且 有显著性的差异(P0.05)。在各运动组中,终身耐力运动组的GADD153/CHOP mRNA 表达量最低。 3、 在各运动组与老年对照组股四头肌内ASK1/JNK mRNA相对表达量的比较中, 老年对照组股四头肌内ASK1/JNK mRNA相对表达量明显高于各运动组,并且有显 著性的差异(P0.05)。终身抗阻运动组、老年抗阻运动组的ASK1/JNK mRNA表达 量显著低于终身耐力运动组和老年耐力运动组。终身抗阻运动组、老年抗阻运动 组的ASK1/JNK mRNA表达量无显著性差异(P0.05)。终身耐力运动组和老年耐力 运动组ASK1/JNK mRNA表达量也无显著性差异(P0.05)。在各运动组与青年对照 组股四头肌内ASK1/JNK mRNA相对表达量的比较中,青年对照组、终身耐力运动 组与老年耐力运动组骨骼肌ASK1/JNK mRNA表达量无显著性差异(P0.05),而终 身抗阻运动组与老年抗阻运动组股四头肌内ASK1/JNK mRNA表达量明显低于各运 动组,并且有显著性的差异(P0.05)。老年耐力运动组的ASK1/JNK mRNA表达量 比终身耐力运动组略低,但并没有显著性差异(P0.05)。 4、 在各运动组与老年对照组股四头肌内Caspase-12 mRNA相对表达量的比较中, 老年对照组股四头肌内Caspase-12 mRNA相对表达量明显高于各运动组,并且具 有显著性的差异(P0.05)。在各运动组中,终身耐力运动组与终身抗阻运动组 的Caspase-12 mRNA表达量明显低于老年耐力运动组与老年抗阻运动组,且具有 显著性差异(P0.05)。在各运动组与青年对照组股四头肌内Caspase-12 mRNA 相对表达量的比较中,青年对照组股四头肌内Caspase-12 mRNA相对表达量明显 高于各运动组,并且具有显著性的差异(P0.05)。终身耐力运动组、终身抗阻 运动组与老年耐力运动组、老年抗阻运动组之间Caspase-12 mRNA表达量无显著 性差异P0.05。 结论: 1、HE染色实验结果说明在对抗骨骼肌衰减的过程中,抗阻运动是延缓骨骼肌衰 减的首选运动方式。虽然耐力运动也在一定程度上延缓了Sarcopenia的发生,当 耐力运动的干预效果不如抗阻运动明显。各运动组的研究结果都取得了对抗骨骼 肌衰减的作用效果,说明预定的运动模式对小鼠骨骼肌细胞结构是有影响的。 2、与老年对照组相比,耐力运动和抗阻运动均可以使小鼠股四头肌内 GADD153/CHOP mRNA表达量显著降低,提示不同的运动方式均可以抑制骨骼肌内 GADD153/CHOP mRNA表达。与青年对照组相比,各运动组股四头肌内GADD153/CHOP mRNA表达量显著降低,说明耐力运动与抗阻运动可以抑制骨骼肌细胞的凋亡,且 不受运动年限的影响。 3、与老年对照组相比,耐力运动和抗阻运动可以有效的降低小鼠股四头肌内 ASK1/JNK mRNA的表达,且具有显著性,说明不同的运动方式均可以有效的抑制 ASK1/JNK mRNA的表达,但综合比较,抗阻运动抑制ASK1/JNK mRNA的表达的作用 效果更为显著,说明抗阻运动在抵抗骨骼肌衰减方面意义重大。与青年对照组相 比,老年抗阻运动组和终身抗阻运动组的ASK1/JNK mRNA的表达显著低于老年耐 力运动组、终身耐力运动组和青年对照组,说明抗阻运动在抑制ASK1/JNK mRNA 的表达面效果显著。 4、与老年对照组相比,耐力运动和抗阻运动均可以有效的降低小鼠股四头内 Caspase-12 mRNA的表达,且具有显著性。提示不同方式的运动均可以有效 的抑 制骨骼肌Caspase-12 mRNA的表达,但受运动年限的影响,运动年限越长,对 骨 骼肌内Caspase-12 mRNA表达的抑制作用越明显。与青年对照组相比,各运 动组 骨骼肌内Caspase-12 mRNA的表达显著降低,且受运动年限的影响。 关键词:Sarcopenia;耐力运动;抗阻运动;基因表达; GADD153/CHOP;ASK1/JNK; Caspase-12 Abstract At present, population aging has become a global countries and regions need to face and solve problems. Aging of the population in all aspects of human life will have a profound impact, in which older individuals on health care and nursing care intensity is particularly prominent. How to make older individuals enjoy a high quality standard of living has become a close attention to all areas and to address the issue. Elderly individuals to maintain good health is the process of many tissues and organs and body structure and function of the process on the fight recession, which is particularly important against the attenuation of skeletal muscle. According to a large number of epidemiological surveys show that individuals with the attenuation of skeletal muscle during aging serious threat to the health of elderly individuals. With age, the inevitable emergence of individual skeletal muscle mass, volume, and decreased muscle strength, resulting in elderly activity with varying degrees of lossElderly individuals can not make the imum enjoyment of a high level of quality of life, severe cases can affect older individuals more basic physical activity, making the older individual falls, fractures, increase the likelihood of accidents occurring, giving a huge social and family psychological and economic burden. Tufts University Professor Irwin Rosenberg in 1988, the concept put forward Sarcopenia, defined as a place with aging and degenerative pathology of skeletal muscle, manifested as skeletal muscle mass, volume, and decreased muscle strength. Therefore, to study and solve the problem of attenuation of skeletal muscle of older individuals, older persons to improve health, reduce the social and economic burden of great significance. The results show that the parties in recent years, Sarcopenia the occurrence and development is closely related with cell apoptosis, are known to have three major-mediated apoptosis signaling pathways: mitochondrial-mediated apoptosis signaling pathways; death receptor factor signaling pathway and endoplasmic reticulum stress-mediated apoptosis signaling pathways. Mitochondrial damage pathway endogenous pathway and death receptor activation extrinsic pathway and two classical intracellular apoptotic pathway, endoplasmic reticulum stress and apoptosis pathway is activated only in recent years found a kinds of new apoptosis pathway. Therefore, the endoplasmic reticulum stress-mediated apoptosis signaling pathways occur in Sarcopenia clarify the role of the process and its impact around the sports discussion, will help us understand the occurrence of apoptosis associated with Sarcopenia mechanism to intervention by exercise ways to prevent or delay the impact of Sarcopenia to the elderlyThrough observation of long-term and short-term endurance exercise and resistance exercise on the quadriceps cross-sectional area of C57 mice and the quadriceps muscle in GADD153/CHOP, ASK1/JNK and Caspase-12 mRNA expression levels, to study internal and ER stress in different sports apoptosis mediated by the intervention. At the same time for the selection of slow skeletal muscle attenuation of the exercise prescription for feasibility of the method and scientific theoryExperimental Methods: In our study, only 2 of 32-month-old C57 male mice were used as subjects were randomly divided into life-long endurance exercise group LE, life-long resistance exercise group LR, older endurance exercise group OE, old resistance exercise group OR, old sedentary control group OC and young sedentary control group YC. The sample used for endurance exercise treadmill model, weight ladder as a resistance exercise model. Life-long training exercise group was 19 months old in the exercise group trained for 4 months, the quiet control group did not participate in training. After the training process equipment using RT-PCR detection of mouse quadriceps muscle in GADD153/CHOP, ASK1/JNK and Caspase-12 mRNA expression, and the data analyzedExperimental results: , 1 After light microscopy, samples of each group compared with the cross-sectional area of quadriceps muscle fiber density found life-long resistance exercise group and old skeletal muscle resistance exercise group configuration compared with the other groups remain the most intact , compared with the aged control group, life-long endurance exercise endurance exercise group and the older group aged quadriceps cross-sectional area is greater than the control group, and the distribution of muscle fibers compared with the aged control group and more compact. Youth is in the control group as young adults, without any signs of skeletal muscle attenuation, so the conformation of skeletal muscle were normal2, In the exercise group and the aged control group quadriceps GADD153/CHOP mRNA relative expression in comparison, the aged control group GADD153/CHOP mRNA relative expression in the quadriceps was significantly higher than the exercise group, and there significant difference P 0.05. Older endurance exercise group, the elderly group and life-long resistance exercise endurance exercise group showed no significant difference P 0.05. Life-long endurance exercise group GADD153/CHOP mRNA was the lowest. In the exercise group and the young control group quadriceps GADD153/CHOP mRNA relative expression in comparison, the aged control group GADD153/CHOP mRNA relative expression in the quadriceps was significantly higher than the exercise group, and there was significant differences P 0.05. In the exercise group, the life-long endurance exercise group GADD153/CHOP mRNA was the lowest 3, In the exercise group and the aged control group quadriceps ASK1/JNK mRNA relative expression in comparison, the aged control group ASK1/JNK mRNA relative expression in the quadriceps was significantly higher than the exercise group, and there significant difference P 0.05. Older endurance exercise group, life-long resistance exercise group ASK1/JNK mRNA expression was higher than resistance exercise group than the older and life-long endurance exercise group. Older endurance exercise group, life-long resistance exercise group ASK1/JNK mRNA expression was no significant difference P 0.05. Resistance exercise group and life-long endurance exercise group ASK1/JNK mRNA expression was no significant difference P 0.05In the exercise group and the aged control group quadriceps ASK1/JNK mRNA relative expression in comparison, the young control group, life-long endurance exercise endurance exercise group and old group ASK1/JNK mRNA expression in skeletal muscle no significant difference P 0.05, while the life-long resistance exercise group and old group of quadriceps resistance exercise in ASK1/JNK mRNA expression was significantly lower than the exercise group, and there were significant differences P 0.05. Older endurance exercise group ASK1/JNK mRNA expression was slightly lower than the life-long endurance exercise group, but no significant difference P .05 4, In the exercise group and the aged control group within the Caspase-12 mRNA quadriceps relative expression of comparison, the aged control group ASK1/JNK mRNA relative expression in the quadriceps was significantly higher than the exercise group, and has significant difference P 0.05. In the exercise group, exercise group life and lifelong endurance resistance exercise group, Caspase-12 mRNA expression was significantly lower than the endurance exercise group life and lifelong resistance exercise group, and the difference was significant P 0.05. Older endurance exercise group and old resistance exercise group Caspase-12 mRNA expression was no significant difference P 0.05, life-long endurance exercise group and lifelong resistance exercise group Caspase-12 mRNA expression was no significant difference P 0.05. In the exercise group and the young control group in Caspase-12 mRNA quadriceps relative expression of comparison, the young control group within the quadriceps relative expression of Caspase-12 mRNA was significantly higher than the exercise group, and significant differences P 0.05. Older endurance exercise group, the elderly group and life-long resistance exercise endurance exercise group, life-long resistance exercise group Caspase-12 mRNA expression was no significant difference P 0.05 Conclusion: , 1 HE staining experimental results show that skeletal muscle attenuation in the process of confrontation, resistance exercise is a slow decay of the preferred movement pattern in skeletal muscle. Although endurance exercise has to a certain extent, the occurrence of delayed Sarcopenia, when the effect of endurance exercise intervention was significantly better than resistance exercise. The exercise group's findings have been made against the effect of attenuation of skeletal muscle, indicating the intended movement pattern of the mouse cell structure is influential2, Compared with aged control group, endurance exercise and resistance exercise can be made within the GADD153/CHOP mRNA expression in mouse quadriceps was significantly lower, suggesting a different movement pattern can be suppressed within the GADD153/CHOP mRNA expression in skeletal muscleCompared with the young control group, the quadriceps exercise group within the GADD153/CHOP mRNA expression was significantly decreased, indicating that endurance exercise and resistance exercise can inhibit apoptosis in skeletal muscle cells, and the impact of life without movement 3, Compared with the aged control group, endurance exercise and resistance exercise can effectively reduce the mice within the ASK1/JNK mRNA expression in the quadriceps, and significant, indicating that different sports can be an effective way to inhibit the ASK1 / JNK mRNA expression, but comparison of results, resistance exercise ASK1/JNK mRNA expression inhibited the effect even more significant, indicating that resistance exercise in skeletal muscle attenuation in terms of significant resistance. Compared with the young control group, age group and life-long resistance exercise resistance exercise group ASK1/JNK mRNA expression was significantly lower than the old endurance exercise group, lifelong endurance exercise group and the young control group, indicating that resistance exercise in the inhibition of ASK1 / JNK mRNA expression of surface effect is remarkable 4, Compared with the aged control group, endurance exercise and resistance exercise can be effective in reducing mouse shares four of the Caspase-12 mRNA expression, and significant. Suggest different ways of movement in skeletal muscle can be effectively inhibit the expression of Caspase-12 mRNA, but by the movement of life, the longer the campaign period, on the Caspase-12 mRNA in skeletal muscle inhibition of the expression of the more significant. Compared with the young control group, the exercise group skeletal muscle expression of Caspase-12 mRNA decreased significantly, and by the movement of lifeKey s: Sarcopenia; endurance exercise; resistance exercise; gene expression; GADD153/CHOP; ASK1/JNK; Caspase-12 目 录 第一部分文献综述. 1 1前言..1 2 Sarcopenia的概述.2 2.1 Sarcopenia 的概念2 2.2 Sarcopenia 发生的可能机制..3 3 三条介导细胞凋亡的重要信号通路..7 3.1 线粒体介导的细胞凋亡信号通路.8 3.2 死亡受体因子信号通路..8 3.3 内质网应激介导的细胞凋亡信号通路..9 4 内质网应激介导的细胞凋亡信号通路研究现状10 4.1 内质网应激及内质网应激反应10 4.2 内质网应激反应相关的信号通路..11 4.3 GADD153/CHOP研究现状及运动对其影响12 4.4 ASK1/JNK 研究现状14 4.5 Caspase-12 的研究现状..15 5 运动对肌纤维横截面积及肌纤维密度的影响..16 第二部分 实验部分18 1前言.18 2实验材料和方法18 2.1 实验动物.18 2.2 实验动物模型建立19 2.3 训练方案.19 2.4 取材与样本制备.20 2.5 主要试剂与仪器.21 2.6 主要测试指标..22 3主要实验方法..23 3.1HE 染色.23 3.2RT-PCR检测表达24 3.3 数据处理.26 4实验结果26 4.1 各组实验对象股四头肌形态光镜观察结果..26 4.2 各组实验对象股四头肌内 GADD153/CHOP mRNA表达量..28 4.3 各组实验对象股四头肌内 ASK1/JUK mRNA表达量.31 4.4 各组实验对象股四头肌内 Caspase12 mRNA表达量..34 5分析与讨论.37 5.1 耐力运动、抗阻运动对 C57小鼠骨骼肌形态的影响.37 5.2 耐力运动、抗阻运动对 C57小鼠股四头肌内 GADD153/CHOP mRNA表达 的影 响.37 5.3 耐力运动、抗阻运动对 C57小鼠骨骼肌内 ASK/JNK mRNA表达的影 响..39 5.4 耐力运动、抗阻运动对 C57小鼠骨骼肌内 Caspase-12 mRNA表达的影 响40 6结论.41 7总结与展望.42 7.1 本实验的特色与创新.42 7.2 本实验的不足与展望.42 参考文献45 后 记. 50第一部分文献综述 1 前言 人口老龄化是指国家或地区总人口中因年轻人口数量减少,老年人口数量增 多而导致的老年人口占总人口数量比例过大。目前,国际上界定一个国家或地区 是否进入老龄化社会的是,当一个国家或地区 60 岁以上老年人口占人口总 数的 10%,或 65 岁以上老年人口占人口总数的 7%,即意味着这个国家或地区 的人口处于老龄化社会。截止至 2002年,在全世界 186个国家和地区中,有 68 个已进入老龄化社会。目前,世界每 10 个人口中有 1 个老年人,预计到 2050 年,每 5个人中有 1老年人,到 2150年每 3个人中就有 1个老年人。毋庸置疑, [1] 人口老龄化已经成为全球各国家和地区亟需面对和解决的问题 。 1950 年,全世界 60 岁以上的老年人约有 2 亿,1970 年达到了 3 亿,2000 年达到 6 亿,步入 21 世纪,2002 年全球 60 岁以上的老年人总数已经达到 6.06 亿,并且这个数字还在不断递增。据联合国人口司 2010 年最新发布的《世 界人 口老龄化(2009)报告》 (World Populationg Aging)显示,从 1950年到 2009年 将近 60 年间,全球范围内 60 岁以上和 65 岁以上人口所占全球总人口的比例已 经分别从 8%和 5%上升至 11%和 8%。显然,2010年的世界变的更加长寿,只是 [2] 2010年后的长寿世界已经不可避免的步入老龄化时代 。 21 世纪是人口老龄化的时代,步许多发达国家的后尘,1999 年后,中国也 进入了老龄化社会,是较早步入老龄化社会的发展中国家之一。中国由于人口基 数大,是世界上老年人口最多的国家,中国的老年人口数量约占全球老年人口总 量的五分之一。作为全球人口最多的国家,中国的人口老龄化问题已不仅仅是中 国自身的问题,还与世界人口老龄化进程紧密相关。截至 2009 年底,我国老年 人口已增至 1.69 亿,占总人口的 12.79%,且正以年均近 1000 万的增幅大踏步 [3] 前进。21世纪的中国将会不可避免的步入老龄化社会 。 世界人口老龄化发展的历史表明,人口老龄化对人类生活的各个方面都会产 生深远的影响,其中,关于老年个体的医疗保障和护理力度问题尤为突出。如何 让老年个体享受高质量的生活水平已成为各方领域密切关注并着手解决的课题。 1《世界人口老龄化(2009)报告》(World Populationg Aging)提出:“未来的 挑战是,确保世界各地的人们在日益老去的时候有安全和尊严相伴,并且在参与 社会生活时还拥有作为公民的全部权利。”若想攻克这一难关,首先要解决的是 老年个人的健康问题,一个拥有健康体魄的老年人才会最大程度上参与各种社会 [4] 活动,享有国家公民应得权益,履行义务 。老年个体维持身体健康的过程就是 和身体诸多组织和器官的结构与机能上出现衰退抗争的过程,其中对抗骨骼肌的 衰减尤为重要。运动系统的肌肉属于横纹肌,由于绝大多数附着在骨骼,故又名 骨骼肌。人体共有600多条骨骼肌,约占全身总重量的40%,任何的身体活动都 是骨骼肌收缩的成果。根据大量的流行病学调查表明,伴随个体衰老过程中骨骼 肌的衰减严重威胁老年个体的身心健康。随着年龄的增长,个体不可避免的出现 骨骼肌肌肉质量、体积以及肌肉力量下降,造成老年人活动能力出现不同程度的 丧失。使得老年个体无法最大程度享受高水平的生活质量,严重者更会影响老年 个体的基本身体活动水平,使得老年个体跌倒、骨折、发生各种意外的可能性增 加,从而给社会和家庭带来巨大的心理和经济负担。因此研究并解决老年个体骨 [5] 骼肌衰减问题,对于改善老年人健康水平,减轻社会经济负担具有重要意义 。 2 Sarcopenia 的概述 2.1 Sarcopenia 的概念 古往今来,无数王孙贵族、隐士道家都希望青春常驻,长生不老,并花费大 量财力物力去寻求这一方法,然而始终无法得其所愿。在科学发展日新月异的今 天,人类对于自身及地球存在的各种生命体有了充分的了解,对于生命体所出现 生老病死等自然规律也有了清醒的认识。人类的健康观也随之发生了巨大的转 变,我们逐渐认识到:生命的质量比生命的长度更加重要,因此如何提高生命的 质量已成为各方关注的焦点。对于老年个体来说,高血压、心脏病、糖尿病等许 多随年龄增长而凸显的疾病严重的影响了老年个体的生活质量,而随增龄发生的 骨骼肌肌肉质量、体积以及肌肉力量下降也同样是威胁老年个体生活质量的“隐 形杀手”,美国塔夫茨大学的Irwin Rosenberg 教授于1988年提出了Sarcopenia 这一概念,该词最早援引于希腊语,它的前缀Sarco-意指肌肉(flesh),而后 缀-penia意指流失(loss),该词译为骨骼肌衰减综合症,定义为一种随增龄而 [6] 发生的骨骼肌退行性病理现象,表现为骨骼肌肌肉质量、体积及肌肉力量下降 。 2自从这以概念提出以来,吸引了众多国内外学者的关注,经过他们不懈研究,摸 索出了一些切实可行的方法来对抗或延缓老年个体中存在的这种症状。 2.2 Sarcopenia 发生的可能机制 目前为止,关于 Sarcopenia的研究报道未有突破性进展,关于 Sarcopenia是 如何在老年个体中发生及发展的尚无权威定论,国外专家学者从各自研究的 方向 和角度出发,归结出来 Sarcopenia发生的几种可能机制。 2.2.1骨骼肌蛋白合成减少 蛋白质是生命的物质基础,也是构成骨骼肌的重要物质,因此,骨骼