The Secretion of Gastric Mucin

The protective and lubricative r6le of mucus in the gastro-intestinal tract has been reported and studied by many investigators (Claude Bernard (4), Schiff (18), de Klug (12), Whitlow (19), Elliott (7), Pavlov (16), Berg and Jobling (3), Leriche (14), and Bucher (6)). An absolute or relative deficiency of gastric mucus has been frequently suggested as a possible etiologic factor in gastro-duodenal ulcerative disease (Leriche (14), Bucher (6), and Kaufmann (11)). More recently Hurst (10) has concluded that 10 per cent of all individuals are predisposed to ulcer because they have hypersthenic stomachs which secrete an excess of highly acid gastric juice low in visible mucus. He may be quoted, " Moreover, owing to the deficient power of secreting mucus which is characteristic of the hypersthenic stomach, the protection against damage afforded by a layer. of mucus in the hyposthenic stomach is absent." These individuals have gastro-duodenal mucosa which can tolerate normal irritation but when faced with " extraordinary or unusual exigencies will as a result of their hypoprotection secondary to mucus deficiency tend to develop ulcer. It has been suggested that this absence of mucus is due to its digestion by gastric juice but mucus differs from other proteins in the extreme slowness with which it undergoes peptic digestion." The resistance of mucus to peptic digestion has been confirmed by one of us (R. K. A.). The object of this investigation was to determine quantitatively whether the gastric contents of a patient with duodenal ulcer has less mucus after a standard stimulus than is found in the stomach of the average individual. METHOD