Medical Department M, Aarhus University Hospital, DK-8000 C Aarhus, Denmark.
Pediatr Nephrol. 2010 Apr;25(4):705-9. doi: 10.1007/s00467-009-1334-3. Epub 2009 Nov 10.
Skeletal muscle is the major constituent of lean body mass and a major determinant of energy expenditure both at rest and during physical activity. Growth hormone, in turn, influences muscle mass as well as energy expenditure. Growth hormone substitution in adults increases muscle mass by 5-10%, but part of the effect is attributed to rehydration rather than protein accretion. In addition, GH regulates substrate metabolism in muscle and in particular antagonizes insulin-stimulated glucose disposal. This effect is linked to increased free fatty acid (FFA) flux but the molecular mechanisms remain unclear. During fasting, GH-induced insulin resistance may be favorable by reducing the demand of gluconeogenesis from protein. But in the postprandial phase, GH exposure may compromise glucose tolerance via the same mechanisms. Understanding the mechanisms whereby GH antagonizes insulin-stimulated glucose disposal in muscle is an important future research field with implications for a variety of clinical conditions ranging from malnutrition to obesity and type 2 diabetes.
骨骼肌是瘦体重的主要组成部分，也是静息和体力活动时能量消耗的主要决定因素。生长激素反过来也影响肌肉质量和能量消耗。生长激素替代治疗可使成年人的肌肉量增加 5-10%，但部分效果归因于再水化而非蛋白质积累。此外，GH 调节肌肉中的底物代谢，特别是拮抗胰岛素刺激的葡萄糖摄取。这种作用与增加的游离脂肪酸（FFA）通量有关，但分子机制尚不清楚。在禁食期间，GH 诱导的胰岛素抵抗可能通过减少蛋白质来源的糖异生需求而有利。但在餐后阶段，GH 暴露可能通过相同的机制损害葡萄糖耐量。了解 GH 拮抗肌肉中胰岛素刺激的葡萄糖摄取的机制是一个重要的未来研究领域，对从营养不良到肥胖和 2 型糖尿病等多种临床情况都有影响。
