Boulware S D, Tamborlane W V, Matthews L S, Sherwin R S
Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06510.
Am J Physiol. 1992 Jan;262(1 Pt 1):E130-3. doi: 10.1152/ajpendo.1992.262.1.E130.
The metabolic effects of recombinant human insulin-like growth factor I (rhIGF-I) on glucose, amino acid, and free fatty acid (FFA) metabolism were examined in nine healthy nonobese subjects. Each received a 3-h primed continuous infusion of rhIGF-I (20 micrograms/kg bolus, 0.4 microgram.kg-1.min-1) while maintaining euglycemia using an exogenous glucose infusion. Total IGF-I levels increased from 125 +/- 11 to 444 +/- 22 ng/ml, and free IGF-I levels rose from undetectable to 73 +/- 5 ng/ml. Insulin levels fell from 95 +/- 9 to 64 +/- 8 pM, and C-peptide fell from 453 +/- 48 to 206 +/- 29 pM; circulating glucagon levels also declined from 72 +/- 9 to 42 +/- 4 pg/ml, rhIGF-I produced a two- to threefold increase in glucose uptake as measured by [3H] glucose (from 10.3 +/- 0.6 to 27.4 +/- 3 mumol.kg-1.m-1), and, despite the fall in insulin secretion, there was a marked 60-70% inhibition of hepatic glucose production. Furthermore, FFA and branched-chain amino acids declined by 40-60% (411 +/- 58 to 165 +/- 36 and 406 +/- 23 to 219 +/- 14 microM, respectively). Our data demonstrate that rhIGF-I has potent effects on glucose (hepatic and peripheral), lipid, and amino acid metabolism in normal humans. The scope of the actions of rhIGF-I closely resemble those of insulin, despite a concomitant inhibitory effect on insulin secretion.
在9名健康非肥胖受试者中研究了重组人生长激素释放因子I（rhIGF-I）对葡萄糖、氨基酸和游离脂肪酸（FFA）代谢的影响。每位受试者接受了3小时的rhIGF-I首剂持续输注（20微克/千克推注，0.4微克·千克-1·分钟-1），同时通过外源性葡萄糖输注维持血糖正常。总IGF-I水平从125±11 ng/ml增至444±22 ng/ml，游离IGF-I水平从检测不到升至73±5 ng/ml。胰岛素水平从95±9 pM降至64±8 pM，C肽从453±48 pM降至206±29 pM；循环胰高血糖素水平也从72±9 pg/ml降至42±4 pg/ml。rhIGF-I使[3H]葡萄糖测量的葡萄糖摄取增加了两到三倍（从10.3±0.6至27.4±3微摩尔·千克-1·分钟-1），并且，尽管胰岛素分泌减少，但肝葡萄糖生成仍受到60 - 70%的显著抑制。此外，FFA和支链氨基酸分别下降了40 - 60%（从411±58降至165±36微摩尔，从406±23降至219±14微摩尔）。我们的数据表明，rhIGF-I对正常人体内的葡萄糖（肝脏和外周）、脂质和氨基酸代谢有显著影响。尽管rhIGF-I对胰岛素分泌有抑制作用，但其作用范围与胰岛素非常相似。
