Formation of concentric saccules in murine parietal cells after injection of diazo-oxo-norleucine.

After treatment with various chemical and physical agents, flattened or ring-like saccules may occur in the cytoplasm of parietal cells of the gastric glands of several species of mammals. In the current investigation, similar structures appeared after treatment with high dosages of diazo-oxo-norleucine (DON), a glutamine antagonist. A tentative sequence for their formation is suggested. Saccules formed of unit membrane became abundant in some parietal cells of the treated mice. Single saccules often had narrow lumens and peripheral distensions. The saccules, either singular or several stacked together, became progressively more curved, enclosing a region of cytoplasm that often contained glycogen-like particles and occasionally vesicles or other organelles. Many of the concentric saccules were close to an intracellular canaliculus. Membrane bound cytoplasm containing glycogen-like particles occasionally occurred in the canaliculi, suggesting that exocytosis had occurred. Cytochemistry revealed that glycoproteins were associated with the concentric saccules, probably located on the luminal surface. The glycogen-like particles in all locations stained in a manner characteristic of glycogen. It is suggested that the concentric saccules may form from vesicles of the tubulovesicular system.