Secretion of a Chondroitin Sulfate-Like Substance by the Chief Cells of the Dog Gastric Mucosa.

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Abstract
The chemical nature and cellular derivation of acid aminopolysaccharides in the stomach, especially with SO4, are poorly understood. Chondroitin sulfates A or C-like substance, susceptible to digestion with testicular hyaluronidase in gastric juice from dog Heidenhain and Pavlov fundic pouches were found and appeared both in a free form and combined with pepsin. Concentration and output of chondroitin sulfate were increased in gastric juice collected after urecholine stimulation, where these paralleled that of pepsin. The source of this chondroitin sulfate was determined by the study of the fundic mucosa obtained by biopsy through gastric fistulae in 17 dogs by histoehemistry and radioautography. Sections were stained with alcian and toluidine blue at various pH''s, aldehyde fuchsin and high iron diamine, PAS [periodic acid Schiff], and radioautographed after intravenous injection of Na2 35SO4, before and after digestion with testicular hyaluronidase. A sulfated aminopolysaccharide was present in chief zymogen cells susceptible to testicular hyaluronidase digestion, having characteristics of a chondroitin sulfate A or C, but not B. This sulfated aminopolysaccharide differed histochemically and in its susceptibility to testicular hyaluronidase from the sulfated glycoprotein present in fundic crypt epithelium of the dog gastric mucosa. Due to the inhibitory effect of sulfated polysaccharides on peptic digestion, the presence of a potential pepsin inhibitor in the pepsinogen producing cells may be significant, and may prevent the reaction between activated protease and the substrate (gastric mucosa) before the protease (pepsin) is discharged into the gastric lumen.