The parietal cells in duodenal ulcer patients. A quantitative ultrastructural study before and during treatment with cimetidine.

Quantitative ultrastructural analyses of the parietal cells have been performed on eleven patients with chronic duodenal ulcer, before and after 8 weeks' treatment with a histamine H2-receptor antagonist (cimetidine, 1 g/day). The treatment caused a significant decrease of the secretory surface density; this result seems to differ from those of ultrastructural reports on parietal cells when acid secretion is inhibited by vagotomy. Furthermore, it was demonstrated that the profile of the tubulo-vesicles of parietal cells could be seen in three phases, tentatively suggesting that this system is able to take up material from the surrounding cytoplasm by encircling it.