Lactate infusion increases circulating pro-brain-derived neurotrophic factor levels in humans.

Area of Science:

• Exercise Physiology
• Neuroscience
• Molecular Biology

Background:

• Brain-derived neurotrophic factor (BDNF) is crucial for neuroplasticity and brain health, and its levels increase with physical exercise.
• Lactate, a metabolite produced during exercise, is hypothesized to mediate exercise-induced BDNF responses, but its isolated effect is unknown.

Purpose of the Study:

• To investigate the role of lactate, in isolation, on pro-BDNF and mature BDNF (mBDNF) levels in blood and muscle.
• To determine if lactate infusion affects circulatory and muscle BDNF isoforms.

Main Methods:

• 18 healthy volunteers received a 1-hour infusion of sodium lactate or saline.
• Blood and muscle samples were collected pre-infusion, during, and up to 120 minutes post-infusion.
• Pro-BDNF and mBDNF levels were quantified using ELISA and immunoblotting.

Main Results:

• Lactate infusion significantly elevated plasma pro-BDNF levels by 55%-68% compared to saline, persisting throughout recovery.
• Plasma and serum mBDNF levels showed no significant changes after lactate infusion.
• Muscle pro-BDNF levels remained unaltered, but correlated with type I muscle fiber area (fCSA%). Muscle mBDNF was undetectable.

Conclusions:

• Lactate alone influences circulatory pro-BDNF levels, suggesting it may partially mediate the exercise-induced increase in pro-BDNF.
• The findings indicate a specific role for lactate in modulating pro-BDNF, distinct from mBDNF, in response to metabolic changes.