Modification of polypeptide composition in keratinocyte fibrous protein.

The thick paw epidermis of the rat and the guinea pig showed a relatively increased amount of the heaviest fibrous polypeptide compared to the thinner epidermis of back and ear. The hyperplastic epidermis of mouse and rat induced by abrasion or painting with 12-0-tetra-decanoyl-phorbal-13-acetate (TPA) also revealed an increase in the heaviest polypeptide. The fibrous polypeptides of epidermis from scarred skin lacked components present in normal epidermis. Cultured epidermal cells showed a different fibrous polypeptide composition than the parent tissue which was altered when the cells were transplanted to an animal or grown on a dermal substrate in culture. Thus multiple factors such as hyperplasia, the dermis and cellular environment may modify the polypeptides synthesized by the keratinocyte.