Phosphocreatine recovery kinetics as a biomarker to assess therapies targeting mitochondrial function

Motivation: Skeletal muscle phosphocreatine (PCr) recovery rate constant (kPCr) is a measure of oxidative metabolism under mild exercise conditions. Goal(s): To test whether kPCr can be used as a biomarker for therapies targeting mitochondrial function. Approach: kPCr is measured after an isometric exercise in the tibialis anterior muscle of healthy volunteers at 7T with a dual-tuned RF surface coil. RNS60 - an electrokinetically processed saline saturated with oxygen - or placebo were given as an inhalant or by intravenous injection along with baseline experiments to assess changes in mitochondrial metabolism. Results: kPCr was increased on average by 19% after both RNS60 inhalation and IV injection administration. Impact: The acute effect on mitochondrial function by RNS60 requires further studies to investigate possible mechanisms of action. kPCr, a non-invasive and quantitative measure, can be applied as a biomarker in other therapies targeting mitochondrial function.