Tyrosine as a Mechanistic-Based Biomarker for Brain Glycogen Decrease and Supercompensation With Endurance Exercise...

Area of Science:

• Neuroscience
• Exercise Physiology
• Metabolomics

Background:

• Brain glycogen in astrocytes fuels neuronal functions, including memory and endurance.
• Exercise adaptations increase brain glycogen, but molecular mechanisms and biomarkers remain unclear.
• Noradrenaline influences brain glycogen metabolism, suggesting a link to tyrosine.

Purpose of the Study:

• To investigate the molecular mechanisms and identify biomarkers of acute exercise-induced brain glycogen supercompensation.
• To test the hypothesis that blood tyrosine is a mechanistic biomarker for brain glycogen supercompensation.

Main Methods:

• Utilized a rat model for endurance exercise.
• Employed microwave irradiation for accurate brain glycogen detection (cortex, hippocampus, hypothalamus).
• Applied capillary electrophoresis mass spectrometry-based metabolomics to analyze plasma metabolites.

Main Results:

• Endurance exercise induced fatigue markers that recovered within 6 hours post-exercise.
• Brain glycogen decreased during exercise and showed supercompensation within 6 hours.
• Plasma metabolomics revealed significant changes, with brain glycogen negatively correlating with plasma glycogenic amino acids (e.g., tyrosine).

Conclusions:

• Plasma glycogenic amino acids are sensitive indicators of brain glycogen levels during endurance exercise.
• Plasma tyrosine may serve as a valuable biomarker for predicting brain glycogen dynamics due to its role in noradrenaline synthesis.