[Is the reduction of the intragastric output of sialic acid bound to glycoproteins of the mucus an index to its gastric protective effect?].

Basal acid and proteolytic activity as well as sialic acid outputs in gastric juice, considered as markers of mucus glycoproteins erosion, were studied in 26 patients with duodenal ulcer before (D1) and after treatment with Phosphalugel for 4 days (D5). In all 26 patients, Phosphalugel treatment resulted in a greater decrease of proteolytic activity and sialic acid outputs than of acid secretion. In 18 of 26 patients with basal sialic acid outputs greater than 1.000 micrograms/h at D1, acid secretion (p less than 0.05), proteolytic activity and sialic acid outputs (p less than 0.001) were significantly decreased. A significant difference of the slope of the relationships between sialic acid outputs (or concentration) and proteolytic activity outputs (or concentration) was observed at D5 with regard to those obtained at D1. Measurement of sialic acid content in gastric juice could be a tool for the assessment of gastroduodenal protective drugs. The mode of action of Phosphalugel might be related to a reduction of the mucolytic effect of pepsins, a result of an induced cytoprotective process.