在过度高强度间歇训练后,骨肌肉过度伸展的基础是细胞机制
Daiki Watanabe1, Masanobu Wada2
1Graduate School of Sport and Health Sciences, Osaka University of Health and Sport Sciences, Osaka, Japan.
American journal of physiology. Cell physiology
|February 4, 2025
概括
过度的运动训练会导致过度伸展 (OR),性能下降. 这项研究发现,大鼠的OR是由最大肌肉力量的减少引起的,而不仅仅是改变了的敏感性,揭示了关键的细胞机制.
科学领域:
- 运动生理学 运动生理学
- 骨肌肉生物学 骨肌肉生物学
- 疲劳的细胞机制
背景情况:
- 过度伸展 (OR) 是由于过度训练而导致的性能下降,需要长时间的恢复.
- 骨肌收缩功能障碍是OR的疑似原因,但细胞触发因素是未知的.
- 了解OR机制对于运动员和从事定期体育活动的人来说至关重要.
研究的目的:
- 为了阐明由过度运动引起的超伸 (OR) 背后的细胞机制.
- 研究高强度间歇训练 (HIIT) 对骨肌肉功能和细胞组件的影响.
主要方法:
- 鼠每天接受高强度间歇训练 (HIIT) 13天以诱导超越 (OR).
- 测量了同度扭矩,并通过机械剥皮纤维技术分析了II型纤维的生理功能.
- 生物化学分析评估了胃半肌中的蛋白质含量 (α-actinin 2) 和活性 (calpain-3自解).
主要成果:
- 17只老鼠中的11只患有OR,其特征是扭矩下降.
- 过度伸展的 (OR) 肌肉纤维显示出脱极化诱导力的减少和肌纤维Ca2+敏感性的增加.
- 与非超值 (NOR) 纤维相比,OR纤维的最大力降低,calpain-3自解增加,α-actinin 2含量保持不变.
结论:
- 过度HIIT后的超伸 (OR) 主要是由肌纤维细胞最大力降低所驱动的.
- 肌纤维素Ca2+敏感度增加伴随OR,但并不能单独解释性能下降.
- 卡尔帕因-3激活可能在超越 (OR) 过程中观察到的细胞干扰中发挥作用.
相关概念视频
Muscle Recovery and Fatigue
1.9K
Muscle fatigue refers to the decline in a muscle's ability to maintain the force of contraction after prolonged activity. It primarily stems from changes within muscle fibers. Even before experiencing muscle fatigue, one may feel tired and have the urge to stop the activity. This response, known as central fatigue, occurs due to changes in the central nervous system, namely the brain and spinal cord. While there is no single mechanism that induces fatigue, it may serve as a protective...
1.9K
Exercise and Muscle Performance
1.3K
Exercise induces a range of adaptations in muscle tissue, depending on the type and duration of activity. Such physical training can be broadly categorized into two types: endurance exercises and resistance exercises.
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
1.3K
Muscle Stimulation Frequency
2.0K
The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box.
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
2.0K
Cross-bridge Cycle
116.6K
As muscle contracts, the overlap between the thin and thick filaments increases, decreasing the length of the sarcomere—the contractile unit of the muscle—using energy in the form of ATP. At the molecular level, this is a cyclic, multistep process that involves binding and hydrolysis of ATP, and movement of actin by myosin.
116.6K
Motor Unit Stimulation
1.4K
When the neuron of a motor unit fires an action potential, it triggers a series of events, leading to a twitch contraction in the muscle fibers. The process of excitation-contraction coupling is crucial in relaying the action potential to the muscle fibers.
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
1.4K
Relaxation of Skeletal Muscles
3.0K
The period of muscle contraction primarily influences the duration of stimulation at the neuromuscular junction (NMJ), the presence of free calcium ions in the sarcoplasm, and the availability of energy or ATP to support contractions.
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open....
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open....
3.0K


