Bdnf expression in rat skeletal muscle after acute or repeated exercise

Area of Science:

• Molecular biology
• Exercise physiology
• Neuroscience

Background:

• The brain-derived neurotrophic factor (BDNF) gene in rats exhibits a complex structure with multiple 5' untranslated exons and a single 3' coding exon.
• Skeletal muscles express BDNF in an activity-dependent manner, suggesting a role in exercise adaptation.

Purpose of the Study:

• To investigate the effects of acute and repetitive running exercise on BDNF mRNA and protein expression in rat soleus muscle.
• To quantitatively analyze the expression of specific BDNF exons following different exercise regimens.

Main Methods:

• Reverse transcription-polymerase chain reaction (RT-PCR) to analyze total BDNF mRNA levels.
• Real-time RT-PCR for quantitative analysis of BDNF exon expression.
• Western blotting to evaluate muscle BDNF protein levels.

Main Results:

• BDNF mRNA levels increased on the second day after acute exercise.
• Repetitive exercise induced two peaks in BDNF mRNA (2 and 24 hours post-exercise), returning to baseline by 6 hours.
• BDNF protein levels increased post-exercise, accumulating after acute exercise and following mRNA trends after repetitive exercise.

Conclusions:

• Exercise up-regulates BDNF mRNA, with a delayed response after acute exercise.
• Repetitive exercise temporarily suppresses BDNF mRNA expression.
• BDNF protein accumulation differs between acute and repetitive exercise protocols, indicating distinct cellular responses.