Carbohydrate‐rich compounds in the colonic mucosa of man. I. Histochemical characteristics of normal and adenomatous colonic mucosa

The carbohydrate‐rich compounds in the epithelial cells of the colonic mucosa of man are characterized by periodate‐reactivity and the presence of both acid and acetyl radicals. These radicals partially prevent the periodate oxidation, but on the removal of sulfate or acetyl groups the intensity of the PAS‐reaction is greatly increased. The compounds with acid radicals are labile to a mild acid hydrolysis and after deacetylation, also labile to a sialidase digestion, which suggests the presence of an N‐acetyl‐O‐diacetyl‐like form of sialic acid in the colonic mucosubstances. The benign neoplasms (adenomatous polyps and villous papillomas) studied showed more intense reactions for sulfate groups than normal epithelium and also cells with production of neutral mucosubstances only. In certain cases, the cells were very similar to those seen during embryonic development in the epithelium of the digestive tract.