Orskov L, Schmitz O, Jørgensen J O, Arnfred J, Abildgaard N, Christiansen J S, Alberti K G, Orskov H
First University Clinic of Internal Medicine, Kommunehospitalet, Aarhus, Denmark.
J Clin Endocrinol Metab. 1989 Feb;68(2):276-82. doi: 10.1210/jcem-68-2-276.
To determine whether physiological increments in circulating GH concentrations influence glucose-induced glucose uptake (GIGU), two-step sequential hyperglycemic clamp (plasma glucose, 6 and 14 mmol/L) studies were performed in six normal subjects with and without GH infusion (40 ng/kg.min). The latter resulted in serum GH levels of 15 +/- 1 (+/- SE) microgram/L. Infusion of somatostatin (250 micrograms/h during step 1 and 750 micrograms/h during step 2) together with a replacement dose of insulin (1.1 pmol/kg.min) resulted in serum insulin levels comparable to basal levels in both studies. The GIGU ([3-3H]glucose), assessed as the difference between steps 2 and 1 glucose utilization during the final 60 min of each step (150 min) was markedly impaired during GH infusion (with GH, 1.1 +/- 0.2 mg/kg.min; without GH, 3.1 +/- 0.3 mg/kg.min; P less than 0.001). Moreover, the percent increase in glucose uptake was considerably reduced during hypersomatotropinemia (with GH, 44 +/- 9%; without GH, 97 +/- 11%; P less than 0.01). In the GH infusion as well as control studies, endogenous glucose production (EGP) was similar at the two levels of glycemia, whereas GH infusion approximately doubled EGP [2.3 +/- 0.2 vs. 1.1 +/- 0.3 mg/kg.min and 2.0 +/- 0.4 vs. 1.1 +/- 0.4 mg/kg.min (step 1 and 2, respectively)]. We conclude that moderate hypersomatotropinemia for several hours is characterized by impaired GIGU as well as augmented EGP.
为了确定循环中生长激素（GH）浓度的生理性升高是否会影响葡萄糖诱导的葡萄糖摄取（GIGU），对6名正常受试者进行了两步序贯高血糖钳夹试验（血浆葡萄糖浓度分别为6 mmol/L和14 mmol/L），其中3名受试者接受GH输注（40 ng/kg·min），另外3名不接受。后者使血清GH水平达到15±1（±SE）μg/L。在两项研究中，输注生长抑素（第一步为250μg/h，第二步为750μg/h）并补充胰岛素（1.1 pmol/kg·min），使血清胰岛素水平与基础水平相当。GIGU（[3-³H]葡萄糖）通过每一步最后60分钟（共150分钟）步骤2和步骤1之间葡萄糖利用率的差值来评估，在GH输注期间显著受损（接受GH时为1.1±0.2 mg/kg·min；未接受GH时为3.1±0.3 mg/kg·min；P<0.001）。此外，在生长激素过多血症期间，葡萄糖摄取的增加百分比显著降低（接受GH时为44±9%；未接受GH时为97±11%；P<0.01）。在GH输注以及对照研究中，内源性葡萄糖生成（EGP）在两个血糖水平相似，而GH输注使EGP增加了约一倍[分别为2.3±0.2 vs. 1.1±0.3 mg/kg·min和2.0±0.4 vs. 1.1±0.4 mg/kg·min（分别为第一步和第二步）]。我们得出结论，数小时的中度生长激素过多血症的特征是GIGU受损以及EGP增加。
