Establishment of SD rat model on knee osteoarthritis induced by type II collagen enzyme

Objective To establish the knee osteoarthritis(OA) model using type Ⅱ collagen enzyme in SD rats. Methods Twenty SD rats were randomly divided into Group A( model group) and Group B( normal saline control group),in which type Ⅱ collagen enzyme and saline were given by knee injection,respectively,on the 1stand 4thday.Body weight on the 1st,3rdand 7thday,knee joint diameter on the 1stand 4thday were recorded. The subjects were sacrificed on the 7thday for assessment of spleen and pancreas weights,and viscera coefficient,while the the general morphology of the knee joint tissues with HE staining was also observed. Results After modeling,body weight reduced in Group A,while it increased in Group B. The knee joint diameter was significantly larger after modeling than before modeling in Group A( P 0. 01),while there was no significant difference revealed in Group B( P 0. 05). Knee joint diameter in Group A was significantly larger than that in Group B after the modeling( P 0. 01). Early OA was observed in Group A,while no evidence was revealed in Group B. Conclusion By using collagen type Ⅱ enzymes,early knee OA model can be successfully established in SD rats. Body weight,knee joint diameter,spleen and pancreas weights,organ coefficient and knee joint pathology could be applied for study of the pathophysiological features of this OA model.