Sarcoplasmic masses. Enzyme histochemistry and autoradiography.

A comparative enzyme-histochemical study was made of the sarcoplasmic masses in a muscle biopsy specimen from a patient with myotonic dystrophy and those in the jaw-muscle of the Rana temporaria tadpole. The enzyme-histochemical patterns of the two methods proved to be identical. An autoradiographic study was made of the sarcoplasmic masses in the R temporaria tadpole with DL-thyroxine-2-14C and levomethionine 35S. The radioactivity labeled compounds were found to be stored or incorporated mainly in the myofibrillae, and virtually not at all in the sarcoplasmic masses.