Transformation of collagen in osteoarthritic cartilage in rabbits / 中华风湿病学杂志

ABSTRACT

Objective To observe the change of collagen in osteoarthritis and study the pathogenesis of osteoarthritis.Methods The right hind limb of twenty-four adult New Zealand White rabbits were immobilized with plaster cast in extension position for 10,20,30 and 40 days,respectively.Six animals without immobilization served as control.The articular cartilage of the medial femur condyle was harvested for transmission electron microscopy,in-situ hybridization of collagenⅡ,and immunohistochemistry of collagenⅠ,Ⅱ,Ⅲ.Results Transmission electron microscopy showed articular cartilage was destructed from the fine collagen fiber network of tangential zone.The fine collagen fiber network did not contain chondrocyte.Immunohistochemistry and in-situ hybridization showed that in earlier period of osteoarthritis,the collagen typeⅡand its gene expression firstly increased,then decreased with destruction of ultrastructure,and chondrocytes enhanced type Ⅱ collagen expressing and synthesizing mainly in transition zone and upper deep zone.In articular cartilage of osteoarthritis there was type Ⅲ collagen,instead of typeⅠcollagen.Conclusion In osteoarthritis,articular cartilage degenerated from tangential layer,in which collagen can not be repaired after destruction,this may contribute to the chondral degeneration.