Accelerated wear and tear of cartilage in osteoarthritis results in its eventual destruction and joint dysfunction. To understand this degeneration process, relationships must be found between the material properties of cartilage and its biochemistry and microscopic organization. In addition, an understanding must be gained of the balance between synthesis (repair) and degradation. We wish to explore two important questions in this regard: First, how do the various, subtle matrix degradative processes affect the intrinsic biomechanical and electromechanical properties of cartilage? Second, how do environmental forces, in turn, affect cartilage's biosynthetic response? We suggest, first, that electromechanical experiments may provide a sensitive measure of certain degradative changes in cartilage proteoglycans. Furthermore, mechanical and electrical stresses may play an important role in matrix synthesis, and hence in the balance between synthesis and repair. We propose to test the first hypothesis by correlating changes in the streaming potential and stiffness of fresh calf articular cartilage with controlled proteoglycan degradative processes induced by specific enzymatic treatments of the tissue. We propose to test the second hypothesis in the same experimental configuration by correlating proteoglycan and collagen synthetic response to applied mechanical and electrical stresses, using calf cartilage in organ culture.