The Influence Of Doxycycline In Cartilage Degeneration Of Experimental Osteoarthritis

Objective: To investigate the effects of doxycycline on rabbit immobilized osteoarthritis and their mechanism by determine the contents of cartilage collagen-Ⅱand the expression of MMP-13 and uPA. Approached the treated mechanism of tetracyclines,to provided theory and experiment base for the investigation of treatment of ostarthritis.Method:Adopted 36 of healthy clearing albino rabbit,divide to 6 groups trabantly, there were normal group, model group, 4 weeks control group and 8 weeks control group,4 weeks treatment group and 8 weeks treatment group.Normal group routine breed,the rest were manufactured to OA model through braking. After the succeed of model,Control group were normal feeding,spontaneous recovery,no special handling,Treatment group lavaged doxycycline everyday,The animals of each group were sacrificed by batch, After sacrificed, to carry out the observation scores of arthrodial cartilage of morphology,then to obtain arthrodial cartilage of the same weight loading district of condyles of femur,rule dyeing,toluidine blue dyeing,detected by immunohistochemistry.Result:(1)Mankin scores of normal group of arthrodial cartilage by light microscope had normal arthrodial cartilage,Arthrodial cartilage of model group were midrange or severe damage, treatment group were Minor injury.Two control groups and model group had not statistically significant.Treated by doxycycline,two treatment groups had noticeable statistically significant than that in model group and control group at the same time (P<0.01). (2)The express of collagen typeⅡof cartilaginous tissue shows,that the IOD scale of model group were lower than normal group(P < 0.01),Treated by doxycycline,the express of collagen typeⅡin 4 weeks treatment group and 8 weeks treatment group were higher than that in model group and control group at the same time (P<0.01), which in 8 weeks treatment group had not statistically significant than that in normal group. (3)Compared to control group,the express of MMP-13,uPA of cartilaginous tissue of model group were strengher,had significant difference(P<0.01),Treated by doxycycline,the express of MMP-13,uPA of 4 weeks treatment group and 8 weeks treatment group were lower than model group and control group at the same time(P<0.01), 8 weeks treatment group had not statistically significant to control group.Analysis of dependablity of MMP-13,uPA of cartilaginous tissue were direct correlation(r=0.964,P<0.01).Conclusion: Doxycycline postponed the cataplasia of cartilage and improved the structure through inhibited effects to MMPs system and uPA system. Thus build preventive and therapeutic effects to OA.