Vasyukova O V, Kasyanova Yu V, Okorokov P L, Bezlepkina O B
Endocrinology Research Center.
Probl Endokrinol (Mosk). 2021 Aug 10;67(4):36-45. doi: 10.14341/probl12779.
Skeletal muscles make up about 25% of the total mass in children and more than 40% in adults. Studies of the last twenty years have shown that along with the main functions, muscle tissue has hormonal activity. It was found that myocytes are able to release signaling molecules-myokines. They act auto-and paracrine within the muscle, and at a high level-through the systemic circulation, carrying out interactions between skeletal muscles and various organs and tissues, such as the liver, bone and adipose tissue, the brain. It is proved that the key factor in the expression of myokines is physical activity, and their level largely depends on physical fitness, the amount of skeletal muscle mass and its composition (the ratio of fast and slow fibers), on the intensity and duration of physical activity. Myokines have a wide range of physiological effects: myostatin suppresses the growth and differentiation of muscle tissue, and decorin, acting as its antagonist, promotes muscle hypertrophy. Interleukin 6 provides an energy substrate for contracting muscle fibers, fibroblast growth factor 21 activates the mechanisms of energy production during fasting and improves tissue sensitivity to insulin; irisin stimulates thermogenesis, glucose uptake by myocytes, and also contributes to an increase in bone mineral density. The study of myokines is one of the key links in understanding the mechanisms underlying obesity and metabolic complications, the consequences of a sedentary lifestyle, as well as the implementation of the action of physical activity. Taking into account the physiological effects of myokines in the body, in the future they can become therapeutic targets for the treatment of these conditions.
骨骼肌约占儿童总体重的25%，在成人中则超过40%。过去二十年的研究表明，除了主要功能外，肌肉组织还具有激素活性。研究发现，肌细胞能够释放信号分子——肌动蛋白。它们在肌肉内以自分泌和旁分泌的方式起作用，并通过全身循环在高水平上发挥作用，实现骨骼肌与各种器官和组织（如肝脏、骨骼、脂肪组织、大脑）之间的相互作用。事实证明，肌动蛋白表达的关键因素是体育活动，其水平在很大程度上取决于身体素质、骨骼肌质量及其组成（快肌纤维和慢肌纤维的比例）、体育活动的强度和持续时间。肌动蛋白具有广泛的生理作用：肌肉生长抑制素抑制肌肉组织的生长和分化，而核心蛋白聚糖作为其拮抗剂，促进肌肉肥大。白细胞介素6为收缩的肌纤维提供能量底物，成纤维细胞生长因子21在禁食期间激活能量产生机制，并提高组织对胰岛素的敏感性；鸢尾素刺激产热、肌细胞对葡萄糖的摄取，还有助于增加骨矿物质密度。对肌动蛋白的研究是理解肥胖和代谢并发症、久坐生活方式的后果以及体育活动作用机制的关键环节之一。考虑到肌动蛋白在体内的生理作用，未来它们可能成为治疗这些疾病的靶点。
