MEDIATORS OF SKELETAL MUSCLE HYPERTROPHY IN HUMANS

这项拟议研究的长期目标是更好地了解老年男性骨骼肌肥大的控制机制。这与老年男性有关，因为骨骼肌量减少或与年龄相关的骨骼肌块丢失在这一人群中非常普遍。具体地说，我们将研究循环睾酮浓度的变化、阻力训练以及这两种干预措施的组合对骨骼肌肥大的影响，以及骨骼肌肥大的推定介质：胰岛素样生长因子I mRNA、胰岛素样生长因子I蛋白和卫星细胞激活(骨骼肌MyoD和肌生成素浓度)。实验设计如下：1)非干预对照组；2)甲地孕酮给药；3)甲地孕酮给药抵抗训练；4)甲地孕酮每周给药100 mg；5)甲地孕酮每周给药抵抗训练100 mg。

The broad long-term objective of the proposed research is to better understand mechanisms controlling skeletal muscle hypertrophy in elderly men. This is relevant to elderly men as sarcopenia or the age related loss of skeletal muscle mass is highly prevalent in this population. Specifically we will be examining the effects of altered circulating testosterone concentrations, resistance training, and the combination of these two interventions on skeletal muscle hypertrophy and putatative mediators of skeletal muscle hypertrophy: insulin like growth factor I mRNA, insulin like growth factor I protein, and satellite cell activation (skeletal muscle concentrations of MyoD and myogenin). We will alter testosterone concentrations with megestrol acetate and testosterone administration and will induce skeletal muscle hypertrophy with resistance training in the following experimental design: 1) A non-intervention control group; 2) megestrol acetate administration; 3) megestrol acetate administration + resistance training; 4) megestrol acetate administration + 100 mg of testosterone enanthate per week; 5) megestrol acetate administration + resistance training + 100 mg of testosterone enanthate per week.