Carrageenan-induced arthritis in the rat

This study documents a model of carrageenan-induced chronic inflammatory ar thritis in the rat, using quantitative histomorphometric assessment. Ten Sp ritgue-Dawley female rats were randomly assigned to one of two groups. Arth ritis was induced in the right tibiofemoral joint by 7 intra-articular inje ctions of 0.02 mt of 1% carrageenan in the arthritic group over 24 days. Th e control (normal) group was injected with 0.02 mt of saline in the right t ibiofemoral joint. Sagittal sections of the right knee joint (distal femur and proximal tibia) were assessed by histomorphometry using the LECO 2001 i mage analysis system. Articular cartilage thickness, epiphyseal plate thick ness, subchondral bone prate thickness, trabecular bone volume and thicknes s of the synovial lining cell layer were measured. Differences between norm al and arthritic groups were statistically significant for articular cartil age thickness of the femur, epiphyseal plate thickness of both the femur an d tibia, subchondral bone plate thickness of the tibia and the thickness of the synovial lining cell layer. These findings demonstrate that carrageena n-induced arthritic changes are similar to other, established models of art hritis in the rat.