To elucidate the developmental process of the intestinal metaplasia of the stomach,
PNNG was orally administered to dogs and the sequential endoscopic examination was
performed by using the methylene blue staining method. In the early period of the
drug administration dogs showed the findings of erosive gastritis at the antral portion.
In the 42nd experimental week, a clearly stained lesion was observed at the gastric
angle. The histological findings of the biopsy specimen from the stained lesion showed
the elongation of the foveolar epithelium and goblet cell-like mucous cells. Apparently
stained lesion was observed at the antral portion in the 128th week. The close-up
endoscopic appearance was very similar to that of stained intestinal metaplasia seen
in the human stomach. The endoscopic methylene blue staining method as performed in
the experimental dogs could provide useful results in the observation of minute lesions
especially intestinal metaplasia in human stomach. This experiment, and further studies,
may help to elucidate the pathogenesis of the gastric carcinoma in humans.
Intestinal metaplasia - Experimental gastric carcinoma - Endoscopic methylene blue
staining method - PNNG
