Abstract:

Objective:The purpose of this studywas to evaluate the role of cell proliferation and apoptosis in the inflammatory lesionme- diated by recombinanthuman interleukin-1Bon condylar cartilage of temporomandibular joint.Methods:The model of inflammatory lesion of temporomandibular jointin SD ratswas established by intraarticularinjectionwith recombinanthuman interleukin-1B. The expressions of proliferating cell nuclear antigen (PCNA) and apoptosis in cartilage were examined by immunohistochemical staining and Tdt-mediated dUTP nick end labelling (TUNEL) during series time of after injection of recombinant human interleukin-1B. Results:The immunostaiing results showed thatPCNAproteinwas expressed in proliferative zone of condylar cartilage, the positive index of PCNA decreased in proliferative zone after injection of recombinant human interleukin-1B1~30 days, and more obviously in 1~7 days. Apoptotic chondrocytes were mainly located in proliferative zone and the prehypertrophic zones, and the apoptotic chondrocytes increased in proliferative and prehypertrophic zones of condylar cartilage (P<0105).Conclusion:These results sug- gest that suppression of proliferating cell nuclear antigen and high apoptosis of chondrocytes may play an important role in the in- flammatory lesion or in the destructive process of temporomandibular joint osteoarthritis.

Key words: proliferation apoptosis, chondrocyte, inflammatory, lesion