MEDIATORS OF SKELETAL MUSCLE HYPERTROPHY IN HUMANS

该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，因为骨骼肌减少症或与年龄相关的骨骼肌质量损失在这一人群中非常普遍。具体来说，我们将研究循环睾酮浓度的改变、阻力训练以及这两种干预措施的结合对骨骼肌肥大的影响，以及骨骼肌肥大的可能介质：胰岛素样生长因子I mRNA、胰岛素样生长因子I蛋白和卫星细胞活化（骨骼肌中MyoD和肌原素的浓度）。我们将用醋酸甲地孕酮和睾酮给药改变睾酮浓度，并通过阻力训练诱导骨骼肌肥大，实验设计如下：1)无干预对照组；2)醋酸甲地孕酮给药；3)醋酸甲孕酮给药+抗阻训练；4)醋酸甲地孕酮+ enanthate睾酮100mg /周；5)服用醋酸甲地孕酮+抗阻训练+每周100毫克的戊酸睾酮。

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.