Muscle Physiology

Static and dynamic state of the art in vivo ³¹P, ¹³C and ¹H MRS is combined with complementary magnetic resonance imaging modalities, physiological measures and biochemical assays to answer questions related to excersise and nutrition dependence of the metabolism in healthy and diseased sceletal muscle as well as pathophysiologies of the myocardium. Hereby, an important focus is the metabolic syndrom including diabetes and heart failure.

³¹P MRS allows for the detection of ATP, PCr and free phosphate and the determination of muscle pH, Mg+-ion and ADP concentrations. An MR compatible excersise ergometer with visual feedback system was developed that allows for dynamic ³¹P MRS based on any desirable excersise protocol and thus the determination of pH-dependent recovery times and thus creatine kinase rates. The latter can also be determined with saturation transfer experiments.

¹³C MRS and ¹H MRS can give insight into energy storage mechanisms. While ¹H MRS allows for the discrimination of intra-myocellular lipids from extra-myocellular lipids along with the detection of the total trimethyl-amine and creatine content and taurine, ¹³C MRS discriminates saturated and unsaturated fatty acids and is the only way to estimate muscle glycogen resources non-invasively.