The Initial Lesions Caused by Sodium Chloride in Canine Gastric Mucosa.

Etiologic research has shown that sodium chloride contributes to gastric carcinogenecity. We investigated the initial changes of gastric mucosa in the cytoplasmic mucin of superficial epithelium and the surface mucous layer of Beagle dogs after an oral dose of sodium chloride. Animals were sacrificed at 0.5, 1.5, 3.5 and 5.5 hours after dosing with 5 g of sodium chloride filled gelatin capsules. Sodium chloride caused lesions such as degeneration and detachment of epithelium, and erosion of mucosa as early as 0.5 hours after administration. ConA type III mucin, the evidence for the origin from gland mucous cells, increased after treatment and was found to be thick at the area of the lesion with progression of decreased mucin in the surface mucous layer, or where epithelial detachment occurred. Gland mucous cell mucin might be responsible for the protection and healing of gastric epithelium. Sulfomucin, demonstrated by high iron diamine staining, originally in the lower foveolar cells of the gastric pits was widely observed in the superficial epithelium of the luminar surface during the time course of the study. PCNA positive generative cells originally in the ithmus and parietal cells originally below the gastric pits were also found among superficial epithelial cells of the luminar surface. It was suggested that these cells might cover the lesion as well as superficial epithelium next to the detaching part.