title: Myosin heavy chain isoform expression in human extraocular muscles: longitudinal variation and patterns of expression in global and orbital layers.
abstract: BACKGROUND
  We investigated the distribution of myosin heavy chain (MyHC) isoforms along the length of the global and orbital layers of human extraocular muscles (EOMs).
  
  
  METHODS
  Whole muscle tissue extracts of human EOMs were cross-sectioned consecutively and separated into orbital and global layers. The extracts from these layers were subjected to electrophoretic analysis, followed by quantification with scanning densitometry.
  
  
  RESULTS
  MyHC isoforms displayed different distributions along the lengths of EOMs. In the orbital and global layers of all EOMs except for the superior oblique muscle, MyHCeom was enriched in the central regions. MyHCIIa and MyHCI were most abundant in the proximal and distal ends.
  
  
  CONCLUSIONS
  A variation in MyHC isoform expression was apparent along the lengths of human EOMs. These results provide a basis for understanding the molecular mechanisms underlying the functional diversity of EOMs.
authors.affiliation: Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, South Korea.
authors.forename: Kyung-Ah
authors.initials: KA
authors.lastname: Park
authors.forename: Jeonghee
authors.initials: J
authors.lastname: Lim
authors.forename: Seongsoo
authors.initials: S
authors.lastname: Sohn
authors.forename: Sei Yeul
authors.initials: SY
authors.lastname: Oh
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018995:Myosin Heavy Chains / Q000378:metabolism*; D009801:Oculomotor Muscles / Q000033:anatomy & histology / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism
chemical_list: D020033:Protein Isoforms; D018995:Myosin Heavy Chains