Biochemical characterization of cartilage affected by osteochondritis dissecans in the humeral head of dogs.
OBJECTIVE
To determine glycosaminoglycan (GAG) concentration and immunohistochemical staining characteristics of type-I, -II, and -X collagen from cartilage affected by osteochondritis dissecans (OCD) in dogs.


METHODS
31 dogs with OCD and 11 clinically normal purpose-bred dogs.


METHODS
Cartilage samples were evaluated microscopically, and GAG content was determined. Immunohistochemical staining was performed for type-I, -II, and -X collagen. Sections were subjectively evaluated for location and intensity of staining.


RESULTS
Cartilage affected by OCD had a variety of pathologic changes and significantly lower GAG concentrations than did normal cartilage. Normal cartilage had no detectable type-I collagen. For dogs < 9 months of age, cartilage affected by OCD had significantly more type-I collagen but significantly less type-X collagen than did control cartilage. For dogs > 12 months of age, cartilage affected by OCD contained significantly more type-I collagen than did control cartilage. There was a significant negative correlation between immunoreactivity of type-I collagen and that of type-II and -X collagen. A significant positive correlation was found between immunoreactivity of type-II and -X collagen.


CONCLUSIONS
Cartilage affected by OCD contains less GAG, more type-I collagen, and less type-X collagen, compared with normal cartilage. A direct correlation between these changes and the etiopathogenesis of OCD was not established.
Tomlinson
J L
JL
Comparative Orthopaedic Laboratory, College of Veterinary Medicine, University of Missouri-Columbia, 65211, USA.
Cook
J L
JL
Kuroki
K
K
Kreeger
J M
JM
Anderson
M A
MA
D000818:Animals; D002358:Cartilage, Articular / Q000737:chemistry* / Q000473:pathology; D003094:Collagen / Q000378:metabolism; D004283:Dog Diseases / Q000378:metabolism* / Q000473:pathology; D004285:Dogs; D005260:Female; D006025:Glycosaminoglycans / Q000378:metabolism*; D006811:Humerus / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D010008:Osteochondritis Dissecans / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D018709:Statistics, Nonparametric
D006025:Glycosaminoglycans; D003094:Collagen