REDOX MODULATION OF MUSCLE FUNCTION IN MICROGRAVITY

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 具体目的：评价NAC作为人类握力疲劳的对策。 N-乙酰半胱氨酸（NAC;还原巯基供体）在最近的几项研究中已显示出抑制人类肌肉疲劳。 在健康志愿者中进行的实验将优化口服NAC的制剂和剂量，并将测试NAC对向心运动期间的握力和握力疲劳的影响。假设1.口服NAC给药可增加血液硫醇水平并抑制运动诱导的氧化应激，而无不良副作用。 将测试五种NAC剂量和两种制剂（溶液或胶囊），以优化谷胱甘肽保护并最大限度地减少副作用。 假设2. NAC预处理延迟同心握力练习中的任务失败。 最有效的NAC管理协议从实验。1将被测试其延迟疲劳的能力，在一个标准化的协议，意志性的握力练习。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Specific Aim: To evaluate NAC as a countermeasure for handgrip fatigue in humans. N-acetylcysteine (NAC; reduced thiol donor) has been shown to inhibit human muscle fatigue in several recent studies. Experiments in healthy volunteers will optimize the preparation and dosage of oral NAC administration and will test NAC effects on handgrip strength and handgrip fatigue during concentric exercise. Hypothesis 1. Oral NAC administration can increase blood thiol levels and inhibit exercise-induced oxidative stress without undesirable side effects. Five NAC doses and two preparations, solution or capsule, will be tested to optimize glutathione protection and minimize side effects. Hypothesis 2. NAC pretreatment delays task failure during concentric handgrip exercise. The most effective NAC administration protocol from Expt. 1 will be tested for its capacity to delay fatigue during a standardized protocol of volitional handgrip exercise.