INTERMITTENT LOADING INDUCES THE EXPRESSION OF 3-B-3(-) EPITOPE IN CULTURED BOVINE ARTICULAR-CARTILAGE

Objective. To study the effects of intermittent loading on the proteog lycans synthesized in intact cultured articular cartilage. Methods. Se samoid bones carrying articular cartilage were subjected to cyclic loa ding in vitro for one week. A new procedure to fix and decalcify the t issue was developed and an immunohistochemical analysis of the express ion of 3-B-3(-) epitope in the articular cartilage was carried out. Th e proteoglycans synthesized were quantified and studied using CL-2B ch romatography. Results. Loading induced an increase in the synthesis of aggrecan molecules, which were larger and less polydisperse than thos e from control cartilage. Loading also induced the expression of 3-B-3 (-) epitopes on newly synthesized proteoglycans. Conclusion. These cha nges are similar to those found in early experimental and human osteoa rthritis (OA). More variables must be studied, but our results suggest that our model might be suitable to study early events in the onset o f OA.