Age Related Changes in Peripheral Muscle Metabolism

The decline in muscle function during the aging process is important clinically as it reduces strength and exercise capacity, both of which are needed to perform daily activities and to maintain healthy organ function. Skeletal muscle 31P Magnetic Resonance Spectroscopy (MRS) provides non-invasive insight into the metabolic activity, pathophysiology and oxidative state of tissue through measurements of high energy metabolites, such as phosphocreatine (PCr) and adenosine-triphosphate (ATP) in vivo. A dynamic probe (i.e., voluntary exercise) is used to assess the metabolic response to increased workload. The kinetics of metabolites such as PCr, offers a direct quantification of the rate of mitochondrial ATP synthesis. In addition, to assess oxygen delivery and tissue perfusion, the arterial spin labelling (ASL) technique can be used, however, this requires a second bout of exercise.
I will use these two techniques to non-invasively assess skeletal muscle during and after exercise to enable metabolic profiling of the tissue. Furthermore, I will combine the 31P-MRS pulse sequence and the ASL imaging sequence into a single interleaved sequence, which will reduce any potential bias in the second exercise bout and shorten the measurement time. These measurements will be applied to elderly and young volunteers for better understanding of metabolic changes in skeletal muscle during ageing. This work will guide research in lifestyle interventions and drug discovery, dedicated to healthy ageing.