title: Further studies on a unique T-tubular acid phosphatase in avian skeletal muscle.
abstract: With the unique observation, using conventional cytochemistry, of acid phosphatase reaction production in the T-tubules of the posterior latissimus dorsi muscle of the chicken, the possibility of endocytosis of lysosomal enzymes by muscle cells came into question. After testing the substrate specificity of this T-tubular phosphatase, it was clear that the enzyme hydrolysed glucose 6-phosphate and beta-glycerophosphate at pH 5.0 but not cytidine-5'-monophosphate which was hydrolysed by dense bodies and autophagic vacuoles. The cytochemical evidence points to a unique phosphatase present on muscle cell membranes which apparently does not belong to the vacuolar apparatus of skeletal muscle and is not 5'-nucleotidase.
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D002645:Chickens / Q000378:metabolism*; D006651:Histocytochemistry; D009124:Muscle Proteins / Q000032:analysis; D009132:Muscles / Q000201:enzymology* / Q000648:ultrastructure; D010744:Phosphoric Monoester Hydrolases / Q000145:classification
chemical_list: D009124:Muscle Proteins; D000135:Acid Phosphatase; D010744:Phosphoric Monoester Hydrolases