ASSESSMENT OF MITOCHONDRIAL-FUNCTION AND CONTROL IN NORMAL AND DISEASED STATES

Mitochondrial function in muscle in vivo can be quantitatively evaluat ed using 31-phosphorus nuclear magnetic resonance. In resting muscle, the concentrations of ions (e.g. H+, Na+) and two of the major bioener getic components (inorganic phosphate and creatine) are determined by regulated transcellular transport processes. During recovery after exe rcise the kinetics and control of mitochondrial ATP synthesis can be e stablished. During exercise the relative contributions to ATP synthesi s of phosphocreatine (using creatine kinase), anaerobic glycogenolysis and oxidative phosphorylation are dissected and have been shown to ch ange with time. The consequences of mitochondrial lesions and dysfunct ions on these processes have been summarised.