Exercise Induced Mitochondrial Biogenesis

What is it? Mitochondrial content is increased in the muscle due to the stress of physical activity –Greater volume of mitochondria per muscle fiber –Greater ability to synthesize ATP per gram of muscle –Improved endurance! Preservation of glycogen Lower production of H+ Lower free AMP concentration

How can exercise do that? Not quite sure – here are the best guesses: Metabolic disturbances Electrical transmissions via voltage-sensitive membrane proteins Ion fluxes (Ca2+) within the contracting muscles Mechanotransduction via the activation of integrin signaling

Continued… The contraction-induced signals (on previous slide) cause transcriptional activation of nuclear genes This leads to alterations in mRNA stability Increases protein import and mitochondrial DNA copy number Leads to greater muscle mitochondrial content

How does mitochondrial biogenesis affect TCA, Beta Oxidation, ETC, and OXPHOS? Upregulates them! –More mitochondria --> increased oxidative capacity –Less need for glycolysis