Frisch H
Department of Pediatrics, University of Vienna, Austria.
J Endocrinol Invest. 1999;22(5 Suppl):106-9.
The anabolic properties of growth hormone (GH) have been investigated extensively. The effects of GH on normal, hypertrophied and atrophied muscles have been studied previously in animal experiments that demonstrated an increase in muscle weight and size, but no comparable increase in performance or tension. In adults with GH deficiency, the changes in body composition can be corrected by GH treatment; lean body mass and strength increase within a few months. In children with GH deficiency, Turner's syndrome or intrauterine growth retardation, an increase in muscle tissue is seen after treatment with GH. In acromegalics with long-standing GH hypersecretion, the muscle volume is increased, but muscle strength and performance are not improved. These observations gave rise to the interest shown by healthy subjects and athletes in using GH to increase their muscle mass and strength. The improvements in muscle strength obtained by resistance exercise training in healthy older men or young men were not enhanced by additional administration of GH. The larger increases in fat-free mass observed in the GH-treated groups were obviously not due to accretion of contractile protein, but rather to fluid retention or accumulation of connective tissue. In experienced weightlifters, the incorporation of amino acids into skeletal muscle protein was not increased and the rate of whole body protein breakdown was not decreased by short-term administration of GH. The results of a study in power athletes confirm the results of these investigations. The study used GH treatment in power athletes compared with a placebo-control group, and the results indicated no increase in maximal strength during concentric contraction of the biceps and quadriceps muscles, although levels of insulin-like growth factor-I were doubled. In highly trained power athletes with low fat mass and high lean body mass, no additional effect of GH treatment on strength is to be expected.
生长激素（GH）的合成代谢特性已得到广泛研究。此前在动物实验中研究了GH对正常、肥大和萎缩肌肉的影响，结果表明肌肉重量和大小增加，但性能或张力没有相应增加。在生长激素缺乏的成年人中，生长激素治疗可纠正身体成分的变化；瘦体重和力量在几个月内增加。在生长激素缺乏、特纳综合征或宫内生长迟缓的儿童中，用生长激素治疗后可见肌肉组织增加。在长期生长激素分泌过多的肢端肥大症患者中，肌肉体积增加，但肌肉力量和性能并未改善。这些观察结果引起了健康受试者和运动员对使用生长激素来增加肌肉质量和力量的兴趣。在健康老年男性或年轻男性中，通过抗阻运动训练获得的肌肉力量改善并未因额外使用生长激素而增强。在接受生长激素治疗的组中观察到的无脂肪质量的较大增加显然不是由于收缩蛋白的积累，而是由于液体潴留或结缔组织的积累。在有经验的举重运动员中，短期使用生长激素不会增加氨基酸掺入骨骼肌蛋白的量，也不会降低全身蛋白质分解率。一项针对力量型运动员的研究结果证实了这些调查结果。该研究对力量型运动员使用生长激素治疗并与安慰剂对照组进行比较，结果表明，尽管胰岛素样生长因子-I水平翻倍，但肱二头肌和股四头肌等长收缩时的最大力量并未增加。在低体脂和高瘦体重的高水平训练力量型运动员中，预计生长激素治疗对力量没有额外影响。
