UROCANIC ACID IN EPIDERMAL CARCINOGENESIS

[摘要] A polarographically reducible substance present in the epidermis of the mouse, rat and man is urocanic acid. This acid was also present in methylcholanthrene-treated mouse epidermis and in methylcholanthrene-induced papillomas of mouse epidermis. Urocanic acid was absent in methylcholanthrene-induced and transplantable squamous cell carcinomas of mice and in squamous cell carcinomas arising spontaneously in human epidermis. Urocanic acid does not appear to be related to keratinizing capacity since it was absent in carcinogen-induced highly differentiated squamous cell carcinomas. Since carcinogen-induced papillomas of mouse epidermis contained urocanic acid, its absence appears at the time of the malignant transformation of epidermal cells. The carcinomas of both mouse and human epidermis contained nicotinamide which was not detected polarographically in mouse, rat and human epidermis.