title: Increased mRNAs for procollagens and key regulating enzymes in rat skeletal muscle following downhill running.
abstract: The purpose of the study was to investigate pre-translational regulation of collagen expression after a single bout of exercise. We analysed steady-state messenger ribonucleic acid (mRNA) levels for collagen types I, III and IV, alpha- and beta-subunits of prolyl 4-hydroxylase and lysyl oxidase (enzymes modifying procollagen chains), and enzyme activity of prolyl 4-hydroxylase from rat soleus muscle (MS) and the red parts of quadriceps femoris muscle (MQF) after 12 h and after 1, 2, 4, 7 and 14 days of downhill (-13.5 degrees ) treadmill running at a speed of 17 m.min-1 for 130 min. Histological and biochemical assays revealed exercise-induced muscle damage in MQF but not MS. Steady-state mRNA levels for the alpha- and beta-subunits of prolyl 4-hydroxylase in MQF, lysyl oxidase in MS and MQF were increased 12 h after running, whereas prolyl 4-hydroxylase activity did not increase until 2 days after exercise. The mRNA levels for the fibrillar collagens (I and III) and basement membrane type IV collagen significantly increased 1 day and 12 h after exertion, respectively. Peak mRNA levels were observed 2-4 days after running, the increases being more pronounced in MQF than in MS. No significant changes were observed in types I or III collagen at the protein level. Strenuous downhill running thus causes an increase in gene expression for collagen types I and III and their post-translational modifying enzymes in skeletal muscle in a co-ordinated manner. These changes, together with the increased gene expression of type IV collagen, may represent the regenerative response of muscle extracellular matrix to exercise-induced injury and an adaptive response to running exertion.
authors.affiliation: Departments of Biology of Physical Activity and Health Sciences, University of Jyväskylä, P.O. Box 35, FIN-40351 Jyväskylä, Finland.
authors.forename: X Y
authors.initials: XY
authors.lastname: Han
authors.forename: W
authors.initials: W
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Komulainen
authors.forename: S O
authors.initials: SO
authors.lastname: Koskinen
authors.forename: V
authors.initials: V
authors.lastname: Kovanen
authors.forename: V
authors.initials: V
authors.lastname: Vihko
authors.forename: P C
authors.initials: PC
authors.lastname: Trackman
authors.forename: T E
authors.initials: TE
authors.lastname: Takala
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D003094:Collagen / Q000032:analysis / Q000235:genetics; D005260:Female; D005966:Glucuronidase / Q000378:metabolism; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000201:enzymology*; D005082:Physical Exertion / Q000502:physiology*; D011347:Procollagen / Q000235:genetics*; D011393:Procollagen-Proline Dioxygenase / Q000235:genetics; D008249:Protein-Lysine 6-Oxidase / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012420:Running
chemical_list: D011347:Procollagen; D012333:RNA, Messenger; D003094:Collagen; D011393:Procollagen-Proline Dioxygenase; D008249:Protein-Lysine 6-Oxidase; D005966:Glucuronidase