Glycogenosomes in fibres of human normal skeletal muscles. An electron-microscopic study.

Analysis of muscle biopsies from five patients, with no clinical evidence of neuromuscular disorders, showed the presence of membrane-bound structures containing glycogen (glycogenosomes). Occurrence of these structures within human muscle fibres has been usually considered a pathological finding, common to various types of metabolic diseases. Our results provide evidence that glycogenosomes are a normal constituent of human muscle fibre, thereby emphasizing that any relationship between glycogenosomes and a specific pathological condition should be established with great care.