[Ultrastructure of the epithelium of the major pancreatic duct in sheep].

Light-and electron-microscopic and some histochemical investigations on the epithelium or the ductus pancreaticus major were carried out in sheep. At least six different cell types are recognizable: (1) nondifferentiated duct cells; (2) cells containing apical secretory granules; (3) goblet cells; the mucosubstances of type 2 and 3 are PAS- and Alcian-blue-positive, also reacting wih methenamine silver; (4) ciliated cells, containing a single cilium with the microtubular pattern 9+2; (5) tuft cells with extremely long and wide microvilli and a pear-shaped cell body; (6) migrating cells, mainly lymphocytes and some assumed eosinophils, showing reaction to Mg++-activated ATPase.