Antrectomy does not accelerate reversal of omeprazole-induced trophic effects in the rat stomach.
The oxyntic mucosa in the rat stomach is under the influence of circulating gastrin. The histamine-producing enterochromaffin-like (ECL) cells constitute the major endocrine cell population in the oxyntic mucosa. They are notably sensitive to changes in the serum gastrin concentration and respond to long-term hypergastrinemia with hyperplasia, whereas hypogastrinemia induces hypoplasia. In the present study long-term, sustained hypergastrinemia was induced by daily treatment with a high dose of the proton pump inhibitor omeprazole. After 10 weeks omeprazole-treated and control rats were antrectomized, resulting in prompt hypogastrinemia. Antrectomy was followed by a rapid reduction of the thickness of the oxyntic mucosa and a somewhat slower reduction of the ECL cell number in both omeprazole-treated and control rats. The percentage decrease in the ECL cell number with time was similar in both groups; after 2-3 weeks the ECL cell number was half of that before antrectomy in both groups. Interestingly, however, 12 weeks after antrectomy the ECL cell number in the omeprazole-pretreated rats remained elevated compared with untreated rats. The histamine concentration of the oxyntic mucosa was markedly lowered within a week after antrectomy in both omeprazole-treated and control rats. Although antrectomy induces hypogastrinemia and although atrophy develops rapidly in the oxyntic mucosa, the omeprazole-induced ECL cell hyperplasia was not completely reversed by antrectomy during the 12 weeks of examination.
Axelson
J
J
Dept. of Surgery, University of Lund, Sweden.
Håkanson
R
R
Sundler
F
F
D000818:Animals; D001284:Atrophy; D002452:Cell Count; D002470:Cell Survival; D005753:Gastric Mucosa / Q000187:drug effects / Q000473:pathology; D005755:Gastrins / Q000097:blood*; D006965:Hyperplasia; D008297:Male; D009853:Omeprazole / Q000494:pharmacology*; D010295:Parietal Cells, Gastric / Q000187:drug effects* / Q000473:pathology; D011706:Pyloric Antrum / Q000601:surgery*; D051381:Rats; D011919:Rats, Inbred Strains
D005755:Gastrins; D009853:Omeprazole