较低的氧化能力是否会影响肌肉在衰老过程中产生ATP的途径的相对贡献?
Zoe H Smith1, Liam F Fitzgerald1, Rajakumar Nagarajan2
1Department of Kinesiology, Muscle Physiology Laboratory, University of Massachusetts Amherst, Amherst, Massachusetts, United States.
概括
年龄较大的成年人.
科学领域:
- 运动生理学 运动生理学
- 骨肌肉的新陈代谢
- 衰老研究研究 衰老研究
背景情况:
- 骨肌肉通过氧化酸化产生ATP的能力可能随着年龄的增长而下降.
- 氧化能力降低对肌肉收缩期间ATP生产途径的体内利用的影响尚不清楚.
研究的目的:
- 调查老年人氧化能力较低是否导致他们在肌肉收缩期间更依赖非氧化ATP生产.
- 为了比较年轻人和老年人之间对运动的生物能量反应.
主要方法:
- 利用3特斯拉磁共振谱法评估19名年轻人和17名老年人膝关节延伸器收缩期间的骨肌肉ATP生产途径.
- 测量了氧化能力 (kPCr,Vmax) 和估计的ATP从肌酸酶 (ATPCK),糖解 (ATPGLY) 和氧化酸化 (ATPOX) 的产生.
- 在参与者的一个子集中,通过脱氧球蛋白的质子光谱评估了细胞内氧气可用性 (PO2).
主要成果:
- 年长的成年人表现出略低的脂蛋白恢复率 (kPCr),表明氧化能力降低.
- 在年轻人和老年人之间,ATPCK,ATPGLY和ATPOX的绝对率没有显著差异.
- 与年轻肌肉相比,老年肌肉使用的最大氧化能力 (ATPOX为%Vmax) 的百分比更高 (71%对55%).
- 细胞内氧气可用性 (PO2) 在年龄组之间没有差异.
结论:
- 较老的骨肌肉表现出"生物能刚性",通过利用其现有的氧化能力的更高比例来适应能量需求.
- 与假设相反,老年人与年轻人相比没有增加非氧化ATP的产量.
- 这些发现凸显了老化骨肌肉中代谢灵活性的改变.
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