title: Sarcoplasmic masses in equine skeletal muscle.
abstract: Sarcoplasmic masses in humans have been associated with various myopathies, although the significance remains elusive. Similar structures have also been observed in equine muscle. The aim of this study was to determine the frequency of such structures in normal and abnormal equine muscle, and to characterize these structures using histological, histochemical, immunohistochemical, ultrastructural, and morphometric analyses. The histological and histochemical appearance was similar to that of human sarcoplasmic masses with a central or subsarcolemmal distribution. Of interest was a predilection for the gluteus medius muscle in younger horses and type 2B fibers. Ultrastructurally they contained disorganized myofibrils and other cellular components that were not membrane bound and were present in both normal and abnormal equine muscle without a specific disease association, suggesting they are a non-pathological degenerative structure. The relatively frequent occurrence of sarcoplasmic masses in horses may make this species a good model for studying the pathogenesis of these structures.
authors.affiliation: Department of Veterinary Surgical and Radiological Sciences, University of California, Tupper Hall 2112, One Shields Avenue, Davis 95616, USA. araleman@ucdavis.edu
authors.forename: M
authors.initials: M
authors.lastname: Aleman
authors.forename: R A
authors.initials: RA
authors.lastname: Lecouteur
authors.forename: J E
authors.initials: JE
authors.lastname: Nieto
authors.forename: D C
authors.initials: DC
authors.lastname: Williams
authors.forename: N J
authors.initials: NJ
authors.lastname: Stanke
authors.forename: G D
authors.initials: GD
authors.lastname: Shelton
mesh_terms: D000367:Age Factors; D000818:Animals; D015415:Biomarkers; D003593:Cytoplasm / Q000473:pathology / Q000648:ultrastructure; D006734:Horse Diseases / Q000473:pathology* / Q000503:physiopathology; D006736:Horses; D007150:Immunohistochemistry; D046529:Microscopy, Electron, Transmission; D018485:Muscle Fibers, Skeletal / Q000473:pathology* / Q000648:ultrastructure; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000473:pathology* / Q000503:physiopathology / Q000648:ultrastructure; D009133:Muscular Atrophy / Q000473:pathology / Q000503:physiopathology; D009135:Muscular Diseases / Q000473:pathology / Q000503:physiopathology / Q000662:veterinary*; D009210:Myofibrils / Q000473:pathology / Q000648:ultrastructure; D011446:Prospective Studies; D012189:Retrospective Studies
chemical_list: D015415:Biomarkers; D009124:Muscle Proteins