摘要
Measurements of metabolic reactions under physiological conditions have been a challenging problem.In a recent issue of Nature,Bartman et al.designed an isotope-labeling-based method to measure tricarboxylic acid(TCA)fluxes in normal tissue and tumors in mice.The method revealed that primary tumors exhibit lower TCA fluxes compared with normal tissue,consistent with current knowledge.They also found that solid tumors generally exhibit lower energy production rates.Traditional methodologies to study metabolism in animals provide a limited number of flux measurements,such as oxygen consumption,carbon dioxide release,and energy production[1].