Abstract
The histochemical observation of aminopeptidase in the skin undergoing carcinogenesis induced by 20-methylcholanthrene was carried out in accordance with the method of Nachlas, Crawford, and Seligman.
1) Aminopeptidase became demonstrable in the subcutaneous connective tissue adjacent to proliferating epithelium, as the epithelium began to be hyperplastic and to invade peg-like.
2) This enzymatic activity was intense in the adjacent connective tissue as long as the invading property was observed, but diminished in the stadium of promoted carcinization with rich epithelial pearls.
3) Aminopeptidase was also demonstrated in some round cells and mast cells infiltrating in the subcutaneous connective tissue.
