Umpleby A M, Shojaee-Moradie F, Thomason M J, Kelly J M, Skottner A, Sonksen P H, Jones R H
Department of Endocrinology and Chemical Pathology, St Thomas's Campus, UMDS, London, UK.
Eur J Clin Invest. 1994 May;24(5):337-44. doi: 10.1111/j.1365-2362.1994.tb01094.x.
The effect of infusions of recombinant insulin-like growth factor-I (IGF-I) (34, 103 or 688 pmol min-1 kg-1), insulin (3.4, 10.3 or 68.8 pmol min-1 kg-1) or combined infusions (34 pmol IGF-I + 3.4 pmol min-1 kg-1 insulin or 103 pmol IGF-I + 3.4 pmol min-1 kg-1 insulin) on protein metabolism, using an infusion of [1-14C]leucine was investigated in anaesthetized fasted dogs. Leucine concentration, production rate (measure of protein degradation), oxidation rate and non-oxidative disappearance rate (measure of protein synthesis) were decreased in a similar dose dependent manner by the IGF-I and insulin infusions (P < 0.01). The decrease in these measurements of leucine metabolism were greater following 34 pmol IGF-I + 3.4 pmol insulin than with either component infused alone (P < 0.05). Free fatty acid concentrations were decreased by all insulin doses (P < 0.01) but only by 103 and 688 pmol min-1 kg-1 insulin-like growth factor (P < 0.05, P < 0.01). These data demonstrate that IGF-I, like insulin, has a dose dependent effect on protein metabolism and that combined insulin and IGF-I infusions have additive effects on protein metabolism.
在麻醉的禁食犬中，使用[1-14C]亮氨酸输注法，研究了重组胰岛素样生长因子-I（IGF-I）（34、103或688 pmol min-1 kg-1）、胰岛素（3.4、10.3或68.8 pmol min-1 kg-1）或联合输注（34 pmol IGF-I + 3.4 pmol min-1 kg-1胰岛素或103 pmol IGF-I + 3.4 pmol min-1 kg-1胰岛素）对蛋白质代谢的影响。IGF-I和胰岛素输注以相似的剂量依赖性方式降低了亮氨酸浓度、生成率（蛋白质降解的指标）、氧化率和非氧化消失率（蛋白质合成的指标）（P < 0.01）。34 pmol IGF-I + 3.4 pmol胰岛素联合输注后，亮氨酸代谢的这些测量值的下降幅度大于单独输注任何一种成分时（P < 0.05）。所有胰岛素剂量均降低了游离脂肪酸浓度（P < 0.01），但仅103和688 pmol min-1 kg-1胰岛素样生长因子降低了游离脂肪酸浓度（P < 0.05，P < 0.01）。这些数据表明，IGF-I与胰岛素一样，对蛋白质代谢具有剂量依赖性作用，并且胰岛素和IGF-I联合输注对蛋白质代谢具有相加作用。
