Changes in mucus secretion during chemical carcinogenesis in the rat colon.

Adenomatous polyps and adenocarcinomas with variety of the precancerous stages have been induced by intraectally injection of N-methyl-N'-nitro-N-nitrosoguanidine. The aim of our experiments have been to study some quantitative and qualitative changes in mucus secretion both in the neoplasm and in transitional area surrounding tumor. The changes in composition of mucus confirmed by several histochemical methods reflect the earliest morphologically observable stage of malignant transformation in colonic mucosa.