Evaluation of muscle degeneration in inherited muscular dystrophy by nuclear magnetic resonance techniques

Nuclear magnetic resonance (NMR) techniques were applied to study the muscular dystrophy in chicks. The water proton spin-lattice relaxation times (T1) of fast, slow, and mixed muscles and plasma were measured. The T1 values of dystrophic pectoralis major and posterior latissimus dorsi (PLD) were significantly higher than those of the normal pectoralis and PLD muscles. The present results establish a direct relationship between the differences in T1 values and the severity of muscle degeneration. Consistent with this conclusion, it was also found that the T1 values of muscles unaffected in muscular dystrophy, namely, the gastrocnemius, and anterior latissimus dorsi (ALD), were not different between the normal and dystrophic chicks. Although the affected muscles of dystrophic chicks contained higher percent water and fat than those of normal chicks, the results show that the higher T1 values in dystrophic muscles were not solely due to variations in their water content. The increase in the T1 values is principally a result of altered interaction between cellular water and macromolecules in the diseased muscles. These data also point out the potential use of NMR imaging in evaluating muscle degeneration.