Gluconeogenesis and the Cori cycle in 12-, 20-, and 40-h-fasted humans
Gluconeogenesis and the Cori cycle in 12-, 20-, and 40-h-fasted humans
复制标题
DOI：
10.1152/ajpendo.1998.275.3.e537
复制
发表时间：
1998-09-01
影响因子：
5.1
通讯作者：
Tayek, JA
中科院分区：
文献类型：
--
作者：
Katz, J;Tayek, JA
6名受试者在餐后8-9小时开始注射[U-C-13]葡萄糖（0.03-0.05 mg kg-l min-l），利用质量同位素分析和先前描述的方程，测定了这些禁食志愿者葡萄糖的产生、葡萄糖的再循环（Cori循环）、未标记碳将葡萄糖稀释到肝脏乳酸-丙酮酸池和糖异生。A. Tayek和J. Katz。点。[j] .内分泌学杂志。中国生物医学工程学报，2009,35(5):476- 484。于6:00 AM开始预充Il-h连续注射，在3 h后（禁食12 h）和注射结束时（禁食20 h）计算上述参数。另一组5名受试者禁食40 h，上述参数计算同前。在禁食12、20和40小时时，血糖分别为93 +/- 2、83 +/- 2和71 +/- 2 (SE) mg/dl；葡萄糖产量分别为2.3、1.8和1.77 mg。公斤(1)分(1);标记碳的循环利用率分别为8、15、15%，葡萄糖分子（Cori循环）的循环利用率分别为18、35、36%；糖异生对葡萄糖产量的贡献分别为41%、71%和92%，或0.96、1.29和1.64 mg。公斤(1)。分钟(1);其他来源对葡萄糖产量的贡献分别为1.37、0.53和0.15 mg kg（-1）。分钟(1)。葡萄糖的再循环在长时间禁食中对维持血浆葡萄糖浓度很重要。我们在这里证明糖异生可以很容易地测量，并且在禁食40小时后，它占葡萄糖产量的90%。
Six subjects were infused with [U-C-13]glucose (0.03-0.05 mg kg-l min-l) starting 8-9 h after a meal, and the production of glucose, the recycling of glucose (the Cori cycle), the dilution of glucose by unlabeled carbon into the hepatic lactate-pyruvate pool, and gluconeogenesis were determined in these fasted volunteers by use of mass isotopomer analysis and equations previously described [J. A. Tayek and J. Katz. Am. J. Physiol. 272 (Endocrinol. Metab. 35): E476-E484, 1997]. A primed continuous Il-h infusion was started at 6:00 AM, and the above parameters were calculated after 3 h (for the 12-h fast) and at the end of the infusion (for the 20-h fast). Another group of five subjects was fasted for 40 h, and the above parameters were calculated as before. At 12, 20, and 40 h of fasting, respectively, blood glucose was 93 +/- 2, 83 +/- 2, and 71 +/- 2 (SE) mg/dl; glucose production was 2.3, 1.8, and 1.77 mg . kg(-1) min(-1); the recycling of labeled carbon was 8, 15, and 15%, and that of glucose molecules (Cori cycle) was 18, 35, and 36%; the contribution of gluconeogenesis to glucose production was 41, 71, and 92% or 0.96, 1.29, and 1.64 mg . kg(-1) . min(-1); and the contribution of other sources to glucose production was 1.37, 0.53, and 0.15 mg kg(-1) . min(-1). The recycling of glucose is important in prolonged fasting for the maintenance of plasma glucose concentration. We demonstrate here that gluconeogenesis can be easily measured and that it accounts for similar to 90% of glucose production after a 40-h fast.