Localization of non-specific esterase and acid phosphatase in human fibroblast from skeletal muscle atrophy.

The intracellular localization of non-specific esterase and acid phosphatase was investigated in human fibroblast cells from skeletal muscle atrophy. Non-specific esterase and acid phosphatase positive sites were visualized ultrastructurally in the fibroblast. Electron microscopy for the cytochemistry of these enzyme was performed in human atrophic skeletal muscle by using thiol acetate esterase method and GOMORI'S method. Lipofuscin pigment granules in fibroblast cells contain dense pigment, granular matrix and lipid droplet. Reaction products of non-specific esterase are seen in the pigment and granular matrix, and they may therefore be called residual bodies. Reaction products of acid phosphatase and non-specific esterase were found to be located in lysosomes.