Myofibrillar incorporation of 3H (G) L-leucine in pgrogressive muscular dystrophy and motor neuron disease.

A study of the incorporation of hydrogen 3 (3H) leucine into skeletal muscle in patients with human muscular dystrophy and motor neuron disease showed uptake in cytoplasm and myofibrils. The techniques used were light and electron microscopy and autoradiography before and after glycerination (Szent-Gyorgyi). The results indicated an increase of 3H leucine uptake into cytoplasm of the dystrophic muscle and a marked drop in incorporation into structural protein. In the patients with motor neuron disease, the normal incorporation into cytoplasm was seen, with reduced uptake into structural protein. These results showed a different protein synthesis pattern in dystrophic and denervated muscle.