Lactate transported by MCT1 plays an active role in promoting mitochondrial biogenesis and enhancing TCA flux in skeletal muscle.
Level 5 - mechanism / opinion, no new human data
Preclinical animal knockout and mechanistic laboratory study
PubMed 38924407 · doi:10.1126/sciadv.adn4508
What was done
Researchers performed metabolic flux analysis to examine lactate utilization in skeletal muscle and evaluated the effects of skeletal muscle-specific monocarboxylate transporter 1 (MCT1) deletion in mice. They assessed running performance, muscle fiber typing, substrate flux to the tricarboxylic acid (TCA) cycle, mitochondrial protein expression, cellular respiration rate, and the NAD+/SIRT1/PGC-1α pathway.
What was found
The abstract reports directional findings without numerical values or effect sizes. Skeletal muscle mainly used lactate to fuel the TCA cycle. Knockout of MCT1 in skeletal muscle increased running performance, increased oxidative fibers, decreased glycolytic fibers, and enhanced glucose flux to the TCA cycle. MCT1 deficiency also augmented cellular respiration, elevated mitochondrial activity and protein expression, and increased cellular NAD+ levels, SIRT1 activity, and PGC-1α protein expression.
Why it matters
This study defines a mechanism by which MCT1-mediated lactate transport modulates skeletal muscle energy substrate preferences, mitochondrial biogenesis, and exercise capacity in mice.
Limits
The study was conducted exclusively in animal and laboratory models, limiting direct translation to human physiology. The abstract provides no sample sizes, effect magnitudes, or variance metrics. Potential adverse or systemic metabolic consequences of muscle MCT1 deletion were not described in the abstract.
Cited by
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