PROTEINASES AND INHIBITORS

The primary agents responsible for cartilage and bone destruction in j oint diseases are active proteinases degrading collagen and proteoglyc an. All four main classes of proteolytic enzymes are involved in eithe r the normal turnover of connective tissue or its pathological destruc tion. These proteinases are made by different cells found within the j oints. Both extracellular and intracellular pathways exist and individ ual enzymes can be inhibited by specific proteinaceous inhibitors that block their activity. Recent research has implicated the matrix metal loproteinases (MMPs) in many of the processes involved in joint diseas es. Conventional treatments do little to affect the underlying disease processes and recently the use of proteinase inhibitors has been sugg ested as a new therapeutic approach. Inhibitors of proteinases can pre vent the destruction of animal cartilage in model systems and future p atient trials will test the effectiveness of these compounds in vivo.