The Tubulovesicular system of gastric parietal cells is connected to the intracellular canaliculus, rough endoplasmic reticulum and Golgi complex. A study by high resolution scanning electron microscopy

The three-dimensional configuration of the tubulovesicular system of restin g rat gastric parietal cells was determined by ultra-hihg-resolution scanni ng electron microscopy (SEM). Rat gastric mucosae were fixed in 1.0% glutar aldehyde and 0.5% formaldehyde in cacodylate buffer, (334 milliosmoles/kgH( 2)O (mOsm)). To render cytoplasmic membranes visible by SEM, fixed mucosae were frozen and fractured, and the cytoplasm of fractured parietal cells wa s macerated by the aldehydeosmium-DMSO-osmium procedure. With much of the c ell matrix and filaments removed, SEM revealed numerous 30-60 nm tubukes, w hich formed a meshwork and also small cisternae about 100 nm. Some cisternae had a small, central 10 nm. fenestration. The cytoplasmic su rface of the tubules was smooth surfaced but some cisternal areas had attac hed polyribosomes. Isolated vesicles or tubules were not found in adequately macerated parieta l cells. The tubulocisternal network was also connected to the Golgi appara tus. In favorable sites connections of the tubular membranes to the canalic uli were clearly visible. Continuity between these two membrane compartment s suggests the probability of rapid membrane transposition when Cells are s timulated to secrete acid.