title: Effects of exercise on markers of venous remodeling in lungs of horses.
abstract: OBJECTIVE
  To determine the effects of 2 weeks of intense exercise on expression of markers of pulmonary venous remodeling in the caudodorsal and cranioventral regions of the lungs of horses.
  
  
  METHODS
  6 horses.
  
  
  METHODS
  Tissue samples of the caudodorsal and cranioventral regions of lungs were obtained before and after conditioning and 2 weeks of intense exercise. Pulmonary veins were isolated, and a quantitative real-time PCR assay was used to determine mRNA expression of matrix metalloproteinase-2 and -9, tissue inhibitor of metalloproteinase-1 and -2, collagen type I, tenascin-C, endothelin-1, platelet-derived growth factor, transforming growth factor (TGF)-β, and vascular endothelial growth factor (VEGF). Protein expression of collagen (via morphometric analysis) and tenascin-C, TGF-β, and VEGF (via immunohistochemistry) was determined.
  
  
  RESULTS
  Exercise-induced pulmonary hemorrhage was detected in 2 horses after exercise. The mRNA expression of matrix metalloproteinase-2 and -9, tissue inhibitor of metalloproteinase-2, TGF-β, and VEGF was significantly lower in pulmonary veins obtained after exercise versus those obtained before exercise for both the caudodorsal and cranioventral regions of the lungs. Collagen content was significantly higher in tissue samples obtained from the caudodorsal regions of the lungs versus content in samples obtained from the cranioventral regions of the lungs both before and after exercise. Exercise did not alter protein expression of tenascin-C, TGF-β, or VEGF.
  
  
  CONCLUSIONS
  Results of this study indicated 2 weeks of intense exercise did not alter expression of marker genes in a manner expected to favor venous remodeling. Pulmonary venous remodeling is complex, and > 2 weeks of intense exercise may be required to induce such remodeling.
authors: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA. stackali@cvm.msu.edu
authors: Alice
authors: A
authors: Stack
authors: Frederik J
authors: FJ
authors: Derksen
authors: Lorraine M
authors: LM
authors: Sordillo
authors: Kurt J
authors: KJ
authors: Williams
authors: John A
authors: JA
authors: Stick
authors: Christina
authors: C
authors: Brandenberger
authors: Juan P
authors: JP
authors: Steibel
authors: N Edward
authors: NE
authors: Robinson
mesh_terms: D000818:Animals; D024042:Collagen Type I / Q000235:genetics / Q000502:physiology; D005260:Female; D006736:Horses / Q000502:physiology*; D007150:Immunohistochemistry / Q000662:veterinary; D008168:Lung / Q000502:physiology*; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000502:physiology; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000502:physiology; D010805:Physical Conditioning, Animal; D011667:Pulmonary Veins / Q000502:physiology*; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D011897:Random Allocation; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000502:physiology; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000235:genetics / Q000502:physiology; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000502:physiology
chemical_list: D024042:Collagen Type I; D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1; D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A; D019716:Tissue Inhibitor of Metalloproteinase-2; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9