Studies on human gastric mucosal zymogen granules and their zymogens.

Intact human gastric mucosal zymogen granules (ZG) were detected in specimens from surgical resections of one patient with gastric adenocarcinoma and two with benign gastric ulcer. Both large ZG with unilaminar membranes and smaller ZG with trilaminar membranes were identified by electron microscopy. The zymogens in the ZG and in mucosal extracts were separated by gel electrophoresis. Slow-moving Protease (SMP) was seen in the whole mucosal extracts but was absent from ZG. One specimen of pyloric mucosa showed a striking absence of ZG. Despite the absence of ZG, pyloric mucosa showed Pepsinogens 2-5 (constituents of PG I) as well as Pepsinogens 6 and 7 (constituents of PG II) and SMP.