Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California.
Am J Physiol Endocrinol Metab. 2022 Jan 1;322(1):E34-E43. doi: 10.1152/ajpendo.00270.2021. Epub 2021 Nov 1.
The Lactate Shuttle hypothesis is supported by a variety of techniques including mass spectrometry analytics following infusion of carbon-labeled isotopic tracers. However, there has been controversy over whether lactate tracers measure lactate (L) or pyruvate (P) turnover. Here, we review the analytical errors, use of inappropriate tissue and animal models, failure to consider L and P pool sizes in modeling results, inappropriate tracer and blood sampling sites, and failure to anticipate roles of heart and lung parenchyma on L⇔P interactions. With support from magnetic resonance spectroscopy (MRS) and immunocytochemistry, we conclude that carbon-labeled lactate tracers can be used to quantitate lactate fluxes.
乳酸穿梭假说得到了多种技术的支持，包括在输注碳标记同位素示踪剂后进行质谱分析。然而，关于乳酸示踪剂是否测量乳酸（L）或丙酮酸（P）周转率一直存在争议。在这里，我们回顾了分析误差、使用不当的组织和动物模型、在建模结果中不考虑 L 和 P 池大小、不适当的示踪剂和血液采样部位以及未能预测心脏和肺实质在 L⇔P 相互作用中的作用。在磁共振光谱（MRS）和免疫细胞化学的支持下，我们得出结论，碳标记的乳酸示踪剂可用于定量测量乳酸通量。
