Histological analysis of achilles tendons in an overuse rat model.
The purpose of this study was to design an animal model that induces histological changes in Achilles tendons consistent with those cited in the literature for human Achilles tendon disease. Sprague-Dawley rats were subjected to 10 degrees uphill treadmill running on a custom-designed rodent treadmill and at a speed of 17 meters per minute for 1 h, five times per week, over a 12-week treatment period. Subsequent histological analysis revealed alterations in the rat Achilles tendon that were generally consistent with those described in the literature for diseased human tendon tissues. These features include: decreased collagen fiber organization, more intense collagen staining, and increased cell nuclei numbers. Interestingly, though, immunohistochemical cell typing suggests that the observed increased cellularity does not include a significant inflammatory component but is secondary to increased numbers of endothelial cells (i.e., vascularization) and fibroblasts. These histological features likely represent a biological repair/remodeling response resulting from overuse running.
Glazebrook
Mark A
MA
Division of Orthopaedic Surgery, Dalhousie University, Queen Elizabeth II Health Sciences Center, Halifax Infirmary (Room 4867), 1796 Summer Street, Halifax, Nova Scotia. markglazebr@ns.sympatico.ca
Wright
James R
JR
Langman
Maxine
M
Stanish
William D
WD
Lee
J Michael
JM
D000125:Achilles Tendon / Q000293:injuries* / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D002467:Cell Nucleus; D003094:Collagen / Q000378:metabolism; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000473:pathology; D005347:Fibroblasts / Q000473:pathology; D007150:Immunohistochemistry; D010805:Physical Conditioning, Animal / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012420:Running / Q000293:injuries*; D013194:Staining and Labeling; D052256:Tendinopathy / Q000473:pathology* / Q000503:physiopathology; D014746:Vimentin / Q000378:metabolism
D014746:Vimentin; D003094:Collagen