Flakoll P J, Kulaylat M, Frexes-Steed M, Hill J O, Abumrad N N
Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee 37232.
JPEN J Parenter Enteral Nutr. 1991 Mar-Apr;15(2):123-7. doi: 10.1177/0148607191015002123.
The role that amino acids play in regulating exogenous glucose infusion during hyperinsulinemia was examined in overnight-fasted volunteers. Each study consisted of both a 30-minute basal period and a 4-hour experimental period during which insulin was infused at either 0.6, 1.2, 2.5, 5.0, 10, or 20 mU/kg/min with euglycemia maintained. Two protocols were used. In the first (I), subjects were allowed to develop hypoaminoacidemia, and in the second (II), plasma amino acid levels were maintained near basal by frequently monitoring plasma leucine levels in conjunction with exogenous infusion of an L-amino acid solution. The amount of amino acids infused were 0.85 +/- 0.11, 1.53 +/- 0.17, 1.97 +/- 0.13, 2.18 +/- 0.50, 2.78 +/- 0.61, and 2.83 +/- 0.44 mg/kg/min at escalating insulin doses, respectively. When amino acids were infused, the amount of glucose required to maintain euglycemia was lower at each insulin dose used (4.5 +/- 0.3 vs 3.6 +/- 0.4, 7.6 +/- 0.5 vs 6.9 +/- 0.3, 10.4 +/- 1.0 vs 8.7 +/- 0.5, 13.3 +/- 0.8 vs 10.2 +/- 0.4, 14.7 +/- 0.8 vs 11.7 +/- 0.6, and 14.9 +/- 0.6 vs 11.8 +/- 0.8 mg/kg/min at escalating insulin doses, respectively; p less than 0.05). The calculated maximal infusion rates were 15.8 +/- 0.6 vs 12.6 +/- 0.4 mg/kg/min (protocol I vs II, p less than 0.001), while the concentrations required to achieve half-maximal rates were 153 +/- 22 and 134 +/- 22 microU/ml (p = ns), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
在过夜禁食的志愿者中研究了氨基酸在高胰岛素血症期间调节外源性葡萄糖输注中的作用。每项研究均包括一个30分钟的基础期和一个4小时的实验期，在此期间以0.6、1.2、2.5、5.0、10或20 mU/kg/分钟的速率输注胰岛素并维持血糖正常。使用了两种方案。在第一种方案（I）中，受试者出现低氨基酸血症，在第二种方案（II）中，通过频繁监测血浆亮氨酸水平并联合外源性输注L-氨基酸溶液使血浆氨基酸水平维持在接近基础水平。随着胰岛素剂量递增，输注的氨基酸量分别为0.85±0.11、1.53±0.17、1.97±0.13、2.18±0.50、2.78±0.61和2.83±0.44 mg/kg/分钟。输注氨基酸时，在每个使用的胰岛素剂量下维持血糖正常所需的葡萄糖量较低（随着胰岛素剂量递增，分别为4.5±0.3对3.6±0.4、7.6±0.5对6.9±0.3、10.4±1.0对8.7±0.5、13.3±0.8对10.2±0.4、14.7±0.8对11.7±0.6、14.9±0.6对11.8±0.8 mg/kg/分钟；p<0.05）。计算得出的最大输注速率为15.8±0.6对12.6±0.4 mg/kg/分钟（方案I对方案II，p<0.001），而达到半最大速率所需的浓度分别为153±22和134±22 μU/ml（p=无显著性差异）。（摘要截短至250字）
