Ultrastructural identification of caveolae and immunocytochemical as well as biochemical detection of caveolin in chondrocytes

Using fluorescence immunocytochemistry, transmission electron microscopy an d Western blotting, we have shown that caveolae and caveolin are abundant o n chondrocytes of different cartilaginous structures of newborn and adult r at knee joints. Caveolin was detected in chondrocytes of the outer layer of articular cartilage, in the fibrocartilage of the menisci, and in fibrocar tilage-like cells at tendon and ligament insertions. Electron microscopical studies revealed caveolae-like invaginations along the plasmalemmal membra ne of articular chondrocytes and fibrocartilage cells. Immunoblot analysis demonstrated caveolin in detergent-insoluble and soluble complexes isolated from cultured rat chondrocytes.