Alteration of mucins in rat gastric mucosa healing from acetic acid-induced ulcer: An immunohistochemical study using monoclonal antibodies against gastric mucins

We examined the alteration of mucins in the rat gastric mucosa injured with acetic acid by means of an immunohistochemical method using three distinct monoclonal antibodies (MAbs) against the gastric mucins: RGM21, RGM26 and HIK1083, each reacting with the mucin molecule located in the specific regi on and layer of the rat gastric mucosa. An acetic acid induced-ulcer was pr epared in eight-week-old male Wistar rats and the animals were killed at 10 , 20 and 30 days after the acid insult. Even at 10 days, mucous cells posit ive to RGM26, which can only recognize the surface mucous cells of antral r egion in the normal mucosa, emerged at the regenerating epithelia. At 20-30 days, not only the distal side, but also the proximal side of these epithe lia were occupied with the cells strongly stained with this MAb. The reacti on with RGM21, which recognizes the surface epithelial cells of normal corp us mucosa, reduced in the regenerating epithelia. HIK1083 staining indicati ng the gland mucous cells increased around the ulcer area at earlier stage of healing, and the staining area was expanded to the bottom of the regener ating mucosae at 20-30 days. These results indicate a distinguished express ion of the antral-type mucins in the regenerating epithelia during the heal ing process of the acetic acid-induced gastric ulcer.