Immunohistochemistry of articular cartilage from immature beagle dogs dosed with difloxacin.

Abstract

Effects of the fluoroquinolone difloxacin on articular-epiphyseal cartilage in growing beagle dogs have been described by light microscopic, electron microscopic, and biochemical methods. Here we present data from an immunohistochemistry study with humeral head cartilage from 3-mo-old beagle dogs after treatment with 1 or 2 oral doses of 300 mg difloxacin/kg body weight. Dogs were euthanatized either 24 hr (single dose) or 48 hr (2 doses) after onset of dosing, and cartilage tissue was stored at -90 degrees C until it was studied by immunohistochemistry. Antibodies against matrix components (collagen II, fibronectin) as well as antibodies against cellular structures (integrins) were used. After single-dose treatment (24-hr group), cartilage lesions such as clefts were not observed, but increased staining for fibronectin was found in cartilage samples from 5 of 6 animals. Markedly increased staining for fibronectin was also demonstrated in the vicinity of clefts within cartilage of all animals of the 48-hr group. Collagen II staining was homogeneously distributed in cartilage from controls and was slightly reduced in territorial matrix in 2 of 6 dogs of the 48-hr group. Integrin staining on chondrocytes was not significantly affected by difloxacin under the given conditions with the exception of a slight reduction of the alpha v integrin chain in 1 of 5 dogs of the 48-hr group. Overall, the most important results is the finding that fibronectin was a sensitive immunohistochemical marker for change in cartilage samples due to difloxacin treatment in dogs.

• Authors: J E Burkhardt, C Förster, E Lozo, M A Hill, R Stahlmann
• Journal: Toxicologic pathology (Toxicol Pathol) 1997 Sep-Oct Vol. 25 Issue 5 Pg. 475-80 ISSN: 0192-6233 [Print] United States
• PMID: 9323837 (Publication Type: Journal Article)

Chemical References

• Anti-Infective Agents
• Antigens, CD
• Fibronectins
• Fluoroquinolones
• Integrin alphaV
• Ciprofloxacin
• difloxacin
• Collagen

Topics

• Administration, Oral
• Animals
• Anti-Infective Agents (toxicity)
• Antigens, CD (metabolism)
• Arthritis, Experimental (chemically induced, metabolism, pathology)
• Cartilage, Articular (drug effects, metabolism, pathology)
• Ciprofloxacin (analogs & derivatives, toxicity)
• Collagen (metabolism)
• Dogs
• Extracellular Matrix (drug effects, metabolism, pathology)
• Fibronectins (metabolism)
• Fluoroquinolones
• Humerus (drug effects, metabolism)
• Immunohistochemistry (methods)
• Integrin alphaV