Effects Of Strain To The Expression Of GAG Of The Normal And Osteoarthritic Chondrocytes

Objective: To Discuss the changes of GAG secretion in normal and osteoarthritis chondrocytes that stimulated by cyclical tensile strain.Methods: Ten New Zealand white rabbits of three months were divided into two groups randomly,each group 5.The animal model of OA was induced by anterior cruciate ligament transection(ACLT) in animals of experiment group ,and the same process of operation was performed on ones of control group, but no ACLT. After 20 weeks, rabbits were sacrificed and evaluated at two levels: macroscopic and histologic(HE) in all left knees. The OA and normal chondrocytes are stimulated with CTS(5%,10%,15%,6h/d,3days) by the Flexercell4000 Tension System.With the time of 24h,48h,72h,we collected the medium of the cultured chondrocytes Stained with Alcian blue precipitation method to analyse the expression of GAG of the chondrocytes.Results: The knee joints of experiment group had obvious degeneration of articular cartilage compared with control ones. The score of macroscopic and histologic evaluation of experiment group is significantly higher than control one (P<0.05). With the different magnitudes and time intervals,the expression of GAG of normal chondrocytes exceeded the OA chondrocytes,the differences were significant(P<0.05);With the different magnitudes and time intervals,the expression of GAG of normal chondrocytes groups varied,the differences are significant(P<0.05),and with the increasing of the magnitudes and the extenxion of the time, the expression of GAG of normal chondrocytes groups increased.the expression of the OA chondrocytes was greatest with the magnitude of 10%CTS,insteadly,with the magnitude of 15%CTS,the expression of the OA chondrocytes decreased(P<0.05);the expression of the OA chondrocytes is greatest with the time of 48h,insteadly,with the time 72h,the expression of the OA chondrocytes decreased(P<0.05).Conclusion: Flexercell-4000 Mechanical loading system can be cultured in vitro cartilage cells in precise quantitative dynamic mechanical load to load, and from the cellular level on the impact of articular chondrocytes proteoglycan production.OA chondrocytes were able to cope when the force strength and time were changed dramatically. 48h stress the role of 10% to maximize the promotion of OA chondrocytes proteoglycan secretion.