title: Developmentally regulated expression of cytochrome-c oxidase isoforms in regenerating rat skeletal muscle.
abstract: The developmental expression of tissue-specific isoforms of cytochrome-c oxidase (COX) subunit VIII [heart (COX VIII-H) and liver (COX VIII-L)] and the influence of innervation were examined in regenerating fast [extensor digitorum longus (EDL)] and slow (soleus) muscles. In adult muscles, COX VIII-H was the predominant isoform. The COX VIII-L mRNA was expressed 3 days after induction of regeneration, and it progressively decreased after 7, 10, 14, and 30 days of regeneration in both muscles. In contrast, the expression of COX VIII-H mRNA accumulated as myogenesis proceeded to the myotube stage between 7 and 10 days of regeneration and progressively increased to near control levels by 30 days. The influence of innervation on the expression of COX VIII and alpha-actin isoforms was examined in control, innervated, and denervated regenerating muscles at 3 and 10 days. The relative expression of COX VIII-L mRNA in denervated regenerating EDL muscles was significantly greater, while that of COX VIII-H was significantly less than in innervated regenerating EDL muscles after 10 days of regeneration. Similarly, cardiac alpha-actin mRNA levels were elevated in denervated regenerating EDL muscles after 10 days of regeneration. In conclusion, motor innervation influences the transition from the COX VIII-L to COX VIII-H isoform during myogenesis in regenerating muscles.
authors.affiliation: Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
authors.forename: C
authors.initials: C
authors.lastname: Ongvarrasopone
authors.forename: J M
authors.initials: JM
authors.lastname: Kennedy
mesh_terms: D000199:Actins / Q000096:biosynthesis; D000818:Animals; D015152:Blotting, Northern; D003576:Electron Transport Complex IV / Q000096:biosynthesis*; D007527:Isoenzymes / Q000096:biosynthesis*; D008297:Male; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000294:innervation / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012038:Regeneration / Q000502:physiology*
chemical_list: D000199:Actins; D007527:Isoenzymes; D012333:RNA, Messenger; D003576:Electron Transport Complex IV