title: Ultra-high-resolution scanning electron microscopic studies on the membrane system of the rat parietal cells after tetragastrin stimulation.
abstract: The membrane system of the rat parietal cells in the resting state and after stimulation with tetragastrin (gastrin) was examined by ultra-high-resolution scanning electron microscopy after removal of the cytoplasmic matrix by the aldehyde-osmium-DMSO-osmium procedure. The intracellular canaliculus was lined with numerous microvilli. Viewed from the cytoplasmic side, the intracellular canaliculi appeared as an arborized system of cactus-like structures with numerous holes about 100 nm in diameter corresponding to the basal openings of the microvilli. The intracellular canaliculi were more developed after gastrin stimulation than in the resting state. In resting cells, most of the tubulovesicles were isolated, 100-200 nm in diameter, spherical or tubular in shape. After gastrin stimulation, these structures were interconnected by slender tubules of about 30 nm in diameter forming together tubulovesicular network. Stereo SEM views clearly demonstrated that the tubulovesicular network was connected with the intracellular canaliculus by the slender connecting tubulus. The increase in the canalicular membrane area and the depletion of tubulovesicles is explained by the transfer of the tubulovesicular membrane to the intracellular canaliculus. In the resting parietal cell, the microvilli are slender and their interior is packed with microfilaments. After gastrin stimulation, the microvilli are swollen and their interior is edematous. These morphological changes seem to indicate the accumulation of fluid in the microvilli after gastrin stimulation.
authors.affiliation: Department of Surgery, Kochi Medical School, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ogata
authors.forename: K
authors.initials: K
authors.lastname: Araki
authors.forename: Y
authors.initials: Y
authors.lastname: Yamasaki
mesh_terms: D000818:Animals; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D008297:Male; D008855:Microscopy, Electron, Scanning; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D010295:Parietal Cells, Gastric / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D051381:Rats; D017208:Rats, Wistar; D013758:Tetragastrin / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D013758:Tetragastrin