The intracellular localization of kallikrein, trypsin and amylase in dog pancreas.

1. Subcellular organelles containing kallikrein (-ogen), trypsinogen and amylase have been isolated from homogenates of dog pancreas and found on discontinuous sucrose density-gradients to equilibrate with 1.7-1.775 M sucrose.2. The electron microscopic appearance of the isolated enzyme-containing organelles appeared to be identical with that of the secretory (zymogen) granules seen in situ in the acinar cells of the pancreas.3. The sequence of events associated with the storage and intracellular transport of pancreatic secretory enzymes is reviewed. The results obtained in this study have been used to delineate the probable intracellular pathway taken by kallikrein, trypsin and amylase from synthesis to secretion.4. The physiological role of the glandular kallikreins is discussed.