Wisneski J A, Stanley W C, Neese R A, Gertz E W
Department of Medicine, University of California, San Francisco.
J Clin Invest. 1990 May;85(5):1648-56. doi: 10.1172/JCI114616.
The effects of hyperglycemia on myocardial glucose metabolism were investigated in seven healthy male subjects (age 24 +/- 4 yr). [6-14C]Glucose and [U-13C]lactate were infused as tracers. Circulating glucose was elevated to two hyperglycemic levels using a clamp technique for 1 h at each level. The mean arterial glucose concentration was 4.95 +/- 0.29 (control), 8.33 +/- 0.31 and 10.84 +/- 0.60 mumols/ml, respectively. Glucose extraction increased significantly from control (0.15 +/- 0.13 mumols/ml) during each level of the glucose clamp (0.28 +/- 0.12, P less than 0.02, and 0.54 +/- 0.14 mumols/ml, P less than 0.005, respectively). Myocardial production of 14CO2 showed that during control 9 +/- 10% of exogenous glucose was oxidized immediately upon extraction. Despite a significant increase in the amount of exogenous glucose oxidized with level II hyperglycemia, it represented only 32 +/- 10% of the glucose extracted. [13C]Lactate analysis showed that the myocardium was releasing lactate; during control 40 +/- 30% of this lactate was derived from exogenous glucose and during hyperglycemia this value increased to 97 +/- 37% (P less than 0.005). Thus, these data show that during short-term hyperglycemia, myocardial glucose extraction is enhanced. However, despite increases in exogenous glucose oxidation and the contribution of exogenous glucose to lactate release, the majority of the extracted glucose (i.e., 57%) is probably stored as glycogen.
在7名健康男性受试者（年龄24±4岁）中研究了高血糖对心肌葡萄糖代谢的影响。以[6-¹⁴C]葡萄糖和[U-¹³C]乳酸作为示踪剂。使用钳夹技术将循环葡萄糖升高至两个高血糖水平，每个水平持续1小时。平均动脉葡萄糖浓度分别为4.95±0.29（对照）、8.33±0.31和10.84±0.60μmol/ml。在葡萄糖钳夹的每个水平期间，葡萄糖摄取量较对照（0.15±0.13μmol/ml）显著增加（分别为0.28±0.12，P<0.02；以及0.54±0.14μmol/ml，P<0.005）。心肌¹⁴CO₂的生成表明，在对照期间，9±10%的外源性葡萄糖在摄取后立即被氧化。尽管在II级高血糖时氧化的外源性葡萄糖量显著增加，但它仅占摄取葡萄糖的32±10%。[¹³C]乳酸分析表明心肌在释放乳酸；在对照期间，该乳酸的40±30%来源于外源性葡萄糖，在高血糖期间该值增加到97±37%（P<0.005）。因此，这些数据表明，在短期高血糖期间，心肌葡萄糖摄取增强。然而，尽管外源性葡萄糖氧化增加以及外源性葡萄糖对乳酸释放的贡献增加，但大部分摄取的葡萄糖（即57%）可能以糖原形式储存。
