1971 Volume 24 Issue 10 Pages 687-694
Pepstatin is shown to be a specific inhibitor of acid proteases. It also inhibits humangastricsin, but the effect is weaker than against humanpepsin. The content of pepsin and gastricsin in gastric juice of stomach ulcer patients is described and the pepstatin which remains in gastric juice collected at 60 minutes after its administration is also determined. These results and those obtained by the direct measurements of the peptic activity of the gastric juice indicate that a sufficient amount of pepstatin to inhibit pepsin remains in the gastric juice 60 minutes after oral administration. The peptic activity of gastric juice is 0-9.8% of the activity of the gastric juice collected before the administration of pepstatin. A method of testing for peptic activity of gastric juice containing pepstatin is described. Free and bound sialic acid in gastric juice of pylorus-ligated rats treated with pepstatin is determined, and pepstatin was shown to inhibit release of bound sialic acid from the mucous membrane. The activity of pepstatin derivatives are described.