CARBOHYDRATE HISTOCHEMISTRY OF THE APICAL MEMBRANES OF NON-CILIATED BRONCHIOLAR CELLS AND TYPE-II PNEUMOCYTES IN 6 MAMMALIAN-SPECIES

The surface coats of non-ciliated bronchiolar cells and type II pneumo cytes of six mammalian species, human, rabbit, rat, mouse, dog and she ep, were investigated by employing two lectins, Maclura pomifera agglu tinin (MPA) and peanut agglutinin (PNA), and anti-Thomsen-Friedenreich (T) monoclonal antibody. Effects of neuraminidase, galactose oxidase (GO) and periodic acid (PA) on their affinities were also examined. MP A revealed strong affinity for the surface coat of non-ciliated bronch iolar cells and type II pneumocytes in most species examined. These ep ithelial cells largely maintained their reactivity for MPA after oxida tion with GO and PA, and neuraminidase digestion did not alter the rea ctivity. PNA stained these epithelial cells in human, rat and rabbit, prior GO treatment enhanced or engendered the reactivity, and PA oxida tion eliminated it. Anti-T antibody did not bind with any of these cel ls, but after prior neuraminidase digestion, it showed affinity for th e surface coats of non-ciliated cells of dog, and of type II pneumocyt es of human and rabbit. Interposed oxidation with GO and PA completely abolished anti-T reactivity. These findings show that non-ciliated ce lls and type II pneumocytes of different species have almost the same sugar structure on their apical membranes, and that staining with MPA, PNA and anti-T antibody are useful tools to identify non-ciliated cel ls as well as type II pneumocytes at the light microscopic level.