A monoclonal antibody against carbohydrate moiety of rat gastric surface epithelial cell-derived mucin.

A monoclonal antibody (MAb), designated RGM11, was generated against mucin purified from the surface epithelial layer of rat gastric mucosa. RGM11 reacted with the purified mucin which had been attached to the ELISA well. This reaction was inhibited by the oxidation of the ELISA well with periodate, indicating the carbohydrate moiety of the mucin molecule to be the epitope of RGM11. Treatment of the ELISA well with galactose oxidase also reduced the reaction with this MAb, thus suggesting the peripheral galactose and/or N-acetylgalactosamine residues of the carbohydrate moiety of mucin are involved in the epitope structure. Histochemical observation indicated that this MAb was able to stain the formalin fixed-paraffin embedded sections of rat and was positive to the surface mucous cells of corpus and antral region of the stomach and the villus epithelium of the duodenal mucosa, but other organs and tissues of rat so far examined were all negative to this MAb. These results indicate that this newly established MAb, labelled RGM11, might be useful to estimate the physiological changes in gastric surface mucous cells and the role of surface epithelial cell derived mucus in the gastric mucosal defense mechanisms.