Department of Public Health and Clinical Medicines, Occupational and Environmental Medicine, Umeå University, 901 87 Umeå, Sweden.
Department of Anatomy and Cell Biology, Lewis Katz School of Medicine of Temple University, 3500 North Broad St., Philadelphia, PV 19140, USA.
Biomed Res Int. 2019 Sep 30;2019:5040818. doi: 10.1155/2019/5040818. eCollection 2019.
Ca regulatory excitation-contraction coupling properties are key topics of interest in the development of work-related muscle myalgia and may constitute an underlying cause of muscle pain and loss of force generating capacity.
A well-established rat model of high repetition high force (HRHF) work was used to investigate if such exposure leads to an increase in cytosolic Ca concentration ([Ca]) and changes in sarcoplasmic reticulum (SR) vesicle Ca uptake and release rates.
Six weeks exposure of rats to HRHF increased indicators of fatigue, pain behaviors, and [Ca], the latter implied by around 50-100% increases in pCam, as well as in the Ca handling proteins RyR1 and Casq1 accompanied by an ∼10% increased SR Ca uptake rate in extensor and flexor muscles compared to those of control rats. This demonstrated a work-related altered myocellular Ca regulation, SR Ca handling, and SR protein expression.
These disturbances may mirror intracellular changes in early stages of human work-related myalgic muscle. Increased uptake of Ca into the SR may reflect an early adaptation to avoid a sustained detrimental increase in [Ca] similar to the previous findings of deteriorated Ca regulation and impaired function in fatigued human muscle.
钙调节兴奋-收缩偶联特性是与工作相关的肌肉痛发生发展的研究重点，可能是肌肉疼痛和丧失产生力量能力的潜在原因。
采用一种已建立的重复高强度工作（HRHF）大鼠模型，研究这种暴露是否会导致细胞质钙浓度 ([Ca]) 增加以及肌浆网（SR）囊泡 Ca 摄取和释放率的变化。
大鼠 HRHF 暴露 6 周增加了疲劳、疼痛行为的指标，[Ca]增加，pCam 增加了约 50-100%，以及钙处理蛋白 RyR1 和 Casq1 增加，与对照组大鼠相比，伸肌和屈肌的 SR Ca 摄取率增加了约 10%。这表明与工作相关的肌细胞钙调节、SR Ca 处理和 SR 蛋白表达发生了改变。
这些紊乱可能反映了人类与工作相关的肌肉痛早期阶段细胞内的变化。SR 中 Ca 的摄取增加可能反映了一种早期的适应，以避免 [Ca] 的持续有害增加，类似于先前发现的疲劳人类肌肉中钙调节恶化和功能受损。
