Application of lectins for detection of goblet cell glycoconjugate differences in proximal and distal colon of the rat.

Paraffin-embedded mucosal biopsies from proximal and distal colon of male Wistar rats were examined by fluorescence microscopy after labeling with nine fluorescein-conjugated lectins. These were isolated by affinity column chromatography, conjugated to fluorescein isothiocyanate, and used as specific molecular probes to define the labeling patterns of carbohydrate-containing components of colonic goblet cells at both sites. Differential lectin labeling of goblet cells within the colonic crypts was observed in both regions likely reflecting increasing differentiation of these epithelial cells. Furthermore, marked regional differences in goblet cell mucus labeling were also detected, indicating that the carbohydrate components of these mucosal cells differ significantly between proximal and distal colon of the rat. These regional differences suggest that there are significant differences in the biologic characteristics of colonic mucosa from these two sites.