P MR Spectroscopy Study in Mice with Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is the most common fatal form of muscular dystrophy characterized by striated muscle wasting and dysfunction. Patients with DMD have a very high incidence of heart failure, which is increasingly the cause of death in DMD patients. We hypothesize that in the in vivo system, the dystrophic cardiac muscle displays bioenergetic deficits prior to any functional or structural deficits. To address this we developed a complete non invasive 31P magnetic resonance spectroscopy (31P MRS) approach to measure myocardial bioenergetics in the heart in vivo.Six control and nine mdx mice at 5 months of age were used for the study. A standard 3D -Image Selected In vivo Spectroscopy (3D-ISIS) sequence was used to provide complete gradient controlled three-dimensional localization for heart 31P MRS. These studies demonstrated dystrophic hearts have a significant reduction in PCr/ATP ratio compare to normal (1.59±0.13 vs 2.37±0.25, p