Schlicker Lisa, Zhao Gang, Dudek Christian-Alexander, Boers Hanny M, Meyer-Hermann Michael, Jacobs Doris M, Hiller Karsten
Department for Bioinformatics and Biochemistry, Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Brunswick, Germany.
Deutsches Krebsforschungszentrum, Heidelberg, Germany.
Front Nutr. 2022 Mar 10;9:785999. doi: 10.3389/fnut.2022.785999. eCollection 2022.
On an organismal level, metabolism needs to react in a well-orchestrated manner to metabolic challenges such as nutrient uptake. Key metabolic hubs in human blood are pyruvate and lactate, both of which are constantly interconverted by very fast exchange fluxes. The quantitative contribution of different food sources to these metabolite pools remains unclear. Here, we applied i stable isotope labeling to determine postprandial metabolic fluxes in response to two carbohydrate sources of different complexity. Depending on the ingested carbohydrate source, glucose or wheat flour, the net direction of the lactate dehydrogenase, and the alanine amino transferase fluxes were adjusted in a way to ensure sufficient availability, while, at the same time, preventing an overflow in the respective metabolite pools. The systemic lactate pool acts as a metabolic buffer which is fueled in the early- and depleted in the late-postprandial phase and thus plays a key role for systemic metabolic homeostasis.
在机体层面，新陈代谢需要以精心编排的方式对诸如营养物质摄取等代谢挑战做出反应。人体血液中的关键代谢枢纽是丙酮酸和乳酸，二者通过非常快速的交换通量不断相互转化。不同食物来源对这些代谢物池的定量贡献仍不清楚。在此，我们应用13C稳定同位素标记来确定餐后对两种不同复杂程度碳水化合物来源的代谢通量。根据摄入的碳水化合物来源是葡萄糖还是小麦粉，乳酸脱氢酶和丙氨酸氨基转移酶通量的净方向会以确保充足供应的方式进行调整，同时防止相应代谢物池出现溢出。全身乳酸池作为一种代谢缓冲器，在餐后早期被补充，在餐后后期被消耗，因此对全身代谢稳态起着关键作用。
