Isoenzymes and histochemistry of non-specific esterases in normal and cancerous skin

Non-specific esterases in normal and carcinomatous skin of the mouse have been investigated electrophoretically and histochemically. Three esterase bands were obtained on electrophoresis from homogenates of normal skin; homogenates of carcinomas showed an accumulation of esterase-Ia and esterase-Ib.* However, using several ester substrates, substrate-specific patterns were demonstrated in the electrophoresis separations and histochemically in tissue sections. On the electrophoresis separations, α-naphthyl acetate, β-naphthyl acetate, 6-bromo-2-naphthyl acetate, naphthol AS acetate, naphthol AS-D acetate and naphthol AS-LC acetate gave rise to similar patterns, but with α-naphthyl propionate as subsmate, more esterase-Ib was indicated and with 5-bromo-indoxyl acetate a distinctive preponderance. Peripheral or uniformly distributed staining was found histochemically in tumour epithelium using α-naphthyl acetate, α-naphthyl propionate and β-naphthyl acetate, whereas with the substrates of naphthol AS acetate, naphthol AS-D acetate and indoxyl acetate an intermediate pattern of staining related to keratinization was obtained.