TESTOSTERONE ADMINISTRATION TO ELDERLY MEN INCREASES SKELETAL-MUSCLE STRENGTH AND PROTEIN-SYNTHESIS
TESTOSTERONE ADMINISTRATION TO ELDERLY MEN INCREASES SKELETAL-MUSCLE STRENGTH AND PROTEIN-SYNTHESIS
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DOI：
10.1152/ajpendo.1995.269.5.e820
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发表时间：
1995-11-01
影响因子：
5.1
通讯作者：
FERRANDO, A
中科院分区：
文献类型：
--
作者：
URBAN, RJ;BODENBURG, YH;FERRANDO, A
给老年男性注射睾丸素可以增加骨骼肌力量和蛋白质合成。上午好。J.Physiol.269(内分泌。梅塔布。(32)：E820-E826,1995。--随着年龄的增长，男性的肌肉力量会显著减弱，同时血清中的睾酮浓度也会下降。我们研究了6名健康男性[67+/-2(SE)YR]服用睾酮对骨骼肌蛋白质合成、力量和肌肉内胰岛素样生长因子I(IGF-I)系统的影响。血清睾酮浓度在480 ng/dl或更低的老年男性接受睾酮注射4wk，以产生与年轻男性相同的血清浓度。在注射睾酮期间，左右腿肌和股四头肌的肌力(等速测力仪)以及肌肉蛋白质合成率(稳定同位素输注)都有所增加。对肌肉总RNA进行的核糖核酸酶保护分析表明，睾酮增加了IGF-I的mRNA浓度，降低了胰岛素样生长因子结合蛋白-4的mRNA浓度。我们的结论是，增加老年男性的睾丸素浓度会增加骨骼肌蛋白质的合成和力量。这种增加可能是通过刺激肌肉内的IGF-I系统来调节的。
Testosterone administration to elderly men increases skeletal muscle strength and protein synthesis. Am. J. Physiol. 269 (Endocrinol. Metab. 32): E820-E826, 1995.-Aging men develop a significant loss of muscle strength that occurs in conjunction with a decline in serum testosterone concentrations. We investigated the effects of testosterone administration to six healthy men [67 +/- 2 (SE) yr] on skeletal muscle protein synthesis, strength, and the intramuscular insulin-like growth factor I (IGF-I) system. Elderly men with serum testosterone concentrations of 480 ng/dl or less were given testosterone injections for 4 wk to produce serum concentrations equal to those of younger men. During testosterone administration muscle strength (isokinetic dynamometer) increased in both right and left hamstring and quadricep muscles as did the fractional synthetic rate of muscle protein (stable-isotope infusion). Ribonuclease protection assays done on total RNA from muscle showed that testosterone administration increased mRNA concentrations of IGF-I and decreased mRNA concentrations of insulin-like growth factor binding protein-4. We conclude that increasing testosterone concentrations in elderly men increases skeletal muscle protein synthesis and strength. This increase may be mediated by stimulation of the intramuscular IGF-I system.