INVIVO NON-INVASIVE MEASUREMENT OF GLUCOSE DYNAMICS APPLICATION OF GLUCOSE CLAMP AND STABLE ISOTOPE

1.通过高胰岛素钳夹结合口服葡萄糖负荷评估胰岛素刺激的葡萄糖处理：为了分别评估外周组织和肝脏的体内葡萄糖处理，我们开发了一种适用于糖尿病受试者的新的非侵入性方法，将高胰岛素钳夹与口服葡萄糖负荷相结合。通过将该技术应用于非胰岛素依赖型糖尿病患者，我们证实：1）通过3 - 4周强化胰岛素治疗严格控制代谢显著增加了肝脏葡萄糖代谢，而外周组织的胰岛素敏感性没有显著变化; 2）通过自行车运动计测量的中等强度运动（200 kcal）后1小时的肝脏葡萄糖处置显著增加。稳定同位素标记的葡萄糖用于评估葡萄糖周转率的应用：我们应用13 <13>C-葡萄糖作为示踪剂用于测量大鼠中胰岛素钳夹期间的葡萄糖周转率。通过对不同类型的^<13>C-葡萄糖（[1-^<13>C]-、[2-^ C<13>]-、[U-^<13>C]-）的GCMS碎片峰的分析，认为用N-甲基二[三氟乙酰胺]对葡萄糖进行衍生化最适合于准确评价<13>血浆样品中^ C-葡萄糖的富集程度，从而计算葡萄糖的周转率。

1. Evaluation of insulin-stimulated glucose disposal by euglycemic hyperinsulinemic clamp combined with oral glucose loading:In order to assess in vivo glucose handlings by peripheral tissues and liver separately, we developed a new noninvasive method applicable to diabetic subjects by combining hyperinsulinemic euglycemic clamp with an oral glucose load. By applying this technique to in non-insulin dependent diabetics, we documented 1) that strict metabolic control by 3 to 4 weeks' intensified insulin therapy significantly augmented hepatic glucose diposal without significant change in insulin sensitivity of peripheral tissues and 2) that hepatic glucose disposal measured 1 hour after moderate-intensity exercise (200 kcal) by a cycle-ergometer significantly increased.2. Application of stable isotope-labeled glucose for the assessment of glucose turnover rates:we applied ^<13>C-glucose as a tracer for the measurement of glucose turnover rates during insulin clamp in the rats. By analyzing fragment peaks of gas chromatography mass spectrometry (GCMS) of various kinds of ^<13>C-glucose ([1-^<13>C]-,[2-^<13>C]-,[U-^<13>C]-), it was concluded that the derivatization of glucose with N-methyl bis[trifluoroacetamide] is most suitable for the acurate assessment of ^<13>C enrichment in the glucose of plasma samples and therefore for the calculation of glucose turnovers.