Carbohydrate Histochemistry of the Apical Membranes of Non-ciliated Bronchiolar Cells and Type II Pneumocytes in Six Mammalian Species.

Abstract

The surface coats of non-ciliated bronchiolar cells and type II pneumocytes of six mammalian species, human, rabbit, rat, mouse, dog and sheep, were investigated by employing two lectins, Maclura pomifera agglutinin (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. MPA revealed strong affinity for the surface coat of non-ciliated bronchiolar cells and type II pneumocytes in most species examined. These epithelial cells largely maintained their reactivity for MPA after oxidation with GO and PA, and neuraminidase digestion did not alter the reactivity. PNA stained these epithelial cells in human, rat and rabbit, prior GO treatment enhanced or engendered the reactivity, and PA oxidation eliminated it. Anti-T antibody did not bind with any of these cells, but after prior neuraminidase digestion, it showed affinity for the surface coats of non-ciliated cells of dog, and of type II pneumocytes of human and rabbit. Interposed oxidation with GO and PA completely abolished anti-T reactivity. These findings show that non-ciliated cells 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 cells as well as type II pneumocytes at the light microscopic level.