Partial meniscectomy as an experimental model of osteoarthritis in rabbits and protector effect of chloroquine diphosphate

OBJECTIVE: The aim of this study was to develop an experimental model of osteoarthritis (OA) that could reproduce morphologic alterations viewed in this disease and to study the effect of chloroquine diphosphate on cartilage remodeling. METHODS: osteoarthritis was induced in rabbits by performing partial meniscectomy. To establish the experimental disease evolution, three groups of ten animals were sacrificed at 3, 14, 22 weeks after disease induction. To evaluate the effect of chloroquine diphosfate in OA progression, a group of six animals was treated preventively with 3 mg/kg/day, started one month prior to osteoarthritis induction and kept until the day of sacrifice (22 weeks). Histopathological (Masson trychrome, H&E), biochemical and immunofluorescence analyses to types I, II and XI collagens were made in all animals. Mankin's score was employed to quantify the severity of articular damage. RESULTS: The experimental model reproduced all of the alterations observed in osteoarthritis. Animals treated with chloroquine diphosfate did not develop morphological changes found in OA. There was significant preservation of articular cartilage tissue (p < 0,0001), maintenance of cellular morphology (p < 0,0001), proteoglicans, as demonstrated by aniline blue coloration (p < 0,005) and tidemark protection (p < 0,001), besides inhibition of osteophytes formation and absence of type I collagen expression. CONCLUSION: The experimental model of partial meniscectomy reproduces gradually, all the cartilage morphologic changes found in human osteoarthritis. Preliminary study done with choroquine diphosfate indicates that it is a cheap and effective drug to act as condroprotective agent in OA.

experimental osteoarthritis; articular cartilage; chloroquine diphosfate; condroprotector; remodeling

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