ELECTRON-HISTOCHEMICAL DEMONSTRATION OF PHOSPHORYLASE AND ITS INTRACELLULAR DISTRIBUTION IN RAT SKELETAL MUSCLES

抄録

Intracellular distribution of polyglucose synthesized histochemically from glucose-l-phosphate by phosphorylase in rat skeletal muscle was examined on electron microscopic level.
Newly formed polysaccharide bearing specific properties appeared in a granular form finer and less dense than the original glycogen particulates of the muscle bfiers, as described in detail in our previous report. It was in general deposited abundantly in intermyofibrillar spaces and more abundantly in subsarcolemmic areas. The synthesis occured in sarcoplasmic ground substance of these areas frequently showing very close localization with native glycogen particulates remaining in the muscles without resolved into the substrate mixture. Among various organelles in the muscle fibers containing polyglucose, sarcoplasmic reticulum received the most conspicuous influence in its arrangement by abundant deposition of the reaction product. Especially, in subsarcolemmic areas, it was remarkably expanded by the polyglucose accumulation and it divided the areas into many subareas. Whorls of sarcoplasmic reticulum membranes were occasionally observed in polyglucose areas. Nuclei, mitochondria and myofibrils did not reveal any direct relationship with polyglucose.
On the basis of these observations, intracellular localization and distribution of phosphorylase which plays an active role in this reaction was discussed.