ULEX-EUROPEUS AGGLUTININ-I BINDING PATTERN DURING CHEMICAL CARCINOGENESIS IN THE RAT GASTROINTESTINAL-TRACT

Background. Fluorescein isothiocyanate-Ulex europeus agglutinin I stai n (UEA1) was postulated as a prominent histochemical marker for premal ignant mucosa in dimethylhydrazine (DMH)-treated animals. UEA, (evalua ted by two scanning methods) and high iron diamine Alcian blue (HIDAB) stain were used in attempt to detect premalignant colonic mucosa in t his animal model. The authors also examined the influence of the duode nal medium on colonic segments transposed to the upper gastrointestina l tract. Methods. Rats were placed into three groups: those with inter posed intestine, those receiving the sham operation, and controls. Hal f of the animals received DMH, and surviving rats were killed at 2, 4, and 8 months. Results. The authors found no differences in tumor deve lopment in the transposed and nontransposed colons of animals treated with DMH. Several transposed segments of animals without carcinogen in duction showed dysplastic areas. These findings suggest a trophic role of certain duodenal factors in the epithelial kinetics of the transpo sed colons. The authors did not find HIDAB stain useful in the identif ication of premalignant colonic mucosa. The quantitative evaluation me thod of UEA, binding was more reliable. Fifteen percent of all the col on specimens of animals without chemical induction were stained with U EA, with this form of evaluation. Positive staining of the interposed colon samples was the most important factor for these findings. Conclu sions. In this animal model, UEA, staining is a potentially useful mar ker of premalignant mucosa, particularly when the nontransposed distal colon of animals treated with DMH is considered.