Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are known to play important roles in the metabolism of epidermal tissue. Among them, MMP-9 and its relatively specific inhibitor, TIMP-1, have been reported to be involved in a variety of pathophysiological conditions. To detect MMP-9 and TIMP-1 in conditioned medium from keratinocytes in culture, I describe methods of gelatin-zymography and reverse zymography (which are used both qualitatively and quantitatively) and of Western blotting analysis using antibodies specific for each molecule. These methods are useful tools for elucidating the pathophysiology of skin conditions and for seeking new drugs.
