美国普林斯顿大学Joshua D. Rabinowitz研究小组报道哺乳动物组织中糖酵解中间体的来源。相关论文于2021年1月19日在线发表于国际学术期刊《细胞—代谢》。

研究人员在小鼠中使用¹³C示踪定量了糖酵解中间来源：循环葡萄糖、组织内糖原和循环糖原异生的前体。循环葡萄糖是循环乳酸的主要来源，乳酸是组织糖酵解的主要最终产物。然而，循环葡萄糖仅在少数几个组织中高度标记糖酵解性中间体：血液、脾脏、横隔膜肌和比目鱼肌。包括肝脏和股四头肌在内的大部分人体组织糖酵解中间体都来自糖原。

糖异生作用对糖酵解中间体的贡献较小，但也广泛，并且其通量随着生理进食而持续存在。进食能够激活循环葡萄糖和乳酸的氧化来维持葡萄糖稳态，而不是抑制糖异生。因此，身体的主体部分能够缓慢分解内部存储的糖原，同时某些组织迅速将循环葡萄糖分解代谢为乳酸，进而在整个身体中氧化。

据了解，糖酵解在生物体代谢中起着核心作用，但其在哺乳动物组织中的定量输入仍不清楚。

附：英文原文

Title: The Source of Glycolytic Intermediates in Mammalian Tissues

Author: Tara TeSlaa, Caroline R. Bartman, Connor S.R. Jankowski, Zhaoyue Zhang, Xincheng Xu, Xi Xing, Lin Wang, Wenyun Lu, Sheng Hui, Joshua D. Rabinowitz

Issue&Volume: 2021-01-19

Abstract: Glycolysis plays a central role in organismal metabolism, but its quantitative inputsacross mammalian tissues remain unclear. Here we use 13C-tracing in mice to quantify glycolytic intermediate sources: circulating glucose,intra-tissue glycogen, and circulating gluconeogenic precursors. Circulating glucoseis the main source of circulating lactate, the primary end product of tissue glycolysis.Yet circulating glucose highly labels glycolytic intermediates in only a few tissues:blood, spleen, diaphragm, and soleus muscle. Most glycolytic intermediates in thebulk of body tissue, including liver and quadriceps muscle, come instead from glycogen.Gluconeogenesis contributes less but also broadly to glycolytic intermediates, andits flux persists with physiologic feeding (but not hyperinsulinemic clamp). Insteadof suppressing gluconeogenesis, feeding activates oxidation of circulating glucoseand lactate to maintain glucose homeostasis. Thus, the bulk of the body slowly breaksdown internally stored glycogen while select tissues rapidly catabolize circulatingglucose to lactate for oxidation throughout the body.

DOI: 10.1016/j.cmet.2020.12.020

Source: https://www.cell.com/cell-metabolism/fulltext/S1550-4131(20)30728-2