[The ultrastructure of the parietal cells of the stomach and their functional activity]

Submicroscopic changes in the parietal cells of the fundus were compared with the data of spot-film intragastric pH-metry of the same mucosal areas in 18 patients treated at the hospital in the department of therapeutic food deprivation. There were seen no changes in the ultrastructure of the parietal cells after a brief (36-hour) fasting when the pH of the mucous membrane failed to differ from the normal. With increased duration of food deprivation there occurred a gradual alkalinization of the gastric secretion and the pH of the gastric wall shifted from 2.02 after a 3-day food deprivation to 4.8-5.0 after fasting for 20 to 30 days. In accordance, there was a change in the ultrastructure of the parietal cells consisting in flattening and subsequent disappearance of tubulovesicles, a reduction of the lumina of the intracellular channels and shortening of microvilli. The results of comparison of the submicroscopic changes with the data of pH-metry indicated that such submicroscopic shifts corresponded co depression of the functional activity of the parietal cells.