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Lactate Shuttle Hypothesis

Meaning

The Lactate Shuttle Hypothesis is a physiological model proposing that lactate, traditionally viewed as a metabolic waste product, actually serves as a crucial, circulating energy substrate and signaling molecule. This hypothesis posits that lactate is continuously produced by glycolytic cells and then “shuttled” via specific monocarboxylate transporters (MCTs) to other cells and organs, such as muscle fibers, the heart, and the brain, for use as fuel in oxidative phosphorylation. This inter-cellular and intra-cellular transport mechanism highlights the body’s metabolic efficiency and flexibility in energy distribution, particularly during periods of high demand.