Human Skin Collagenase: Localization and Distribution in Normal Human Skin*

Abstract

ABSTRACTCollagenase activity was measured quantitatively from normal human skin cultured on radioactive, native, reconstituted collagen gels. A regional difference in enzyme activity was demonstrated with skin from the scalp having a specific enzyme activity greater than four-fold that of normal body skin. Isolated epidermis and dermis cultured separately revealed that the major site of collagenase production in normal human skin is in the upper or papillary portion of the dermis and that no enzyme activity can be detected in the lower portions of the dermis. The epidermis shows only minimal collagenolytic activity which is in marked contrast to the anuran tadpole where the tailfin epidermis is the major source of collagenase. Freeze-thawing and puromycin blocks the appearance of collagenase in both whole skin and isolated dermis suggesting that de novo synthesis of collagenase occurs during the time of culture.Under certain circumstances, such as in the healing wound edge, the epidermis is capable of actively synthesizing collagenase and acts together with the underlying dermis to provide an enzyme capable of specifically attacking the collagen molecule