ALTHOUGH the gastric glands secrete some of their enzyme product into the blood as a "reflection" of gastric secretion, pepsin levels in the blood or urine indicate potential, not concomitant, gastric secretion.1,2 It is the purpose of this paper to present further observations that, together with gastric-biopsy material, emphasize a possible role of superficial gastritis in accounting for some of the divergences between gastric secretion and the level of blood pepsin or uropepsin.MethodsBlood pepsin levels, gastric pepsin and pH were measured by methods previously described.3 The range of normal blood pepsin levels in this laboratory is between 200 . . .