Relationship between fundic endocrine cells and gastric acid secretion in hypersecretory duodenal ulcer diseases

Acid hypersecretion is associated with duodenal ulcer disease in the following conditions: Zollinger-Ellison syndrome (ZES) and antral gastrin cell hyperfunction (AGCH) due to hypergastrinaemia, or hypersecretory duodenal ulcer (HDU) without hypergastrinaemia.

To evaluate whether quantitative changes in fundic ECL and D cells may be involved in acid hypersecretion.

Seven ZES, six AGCH and six HDU Helicobacter pylori-positive patients were compared. Basal (BAO) and pentagastrin-stimulated gastric acid secretions (PAO), and morphometry of fundic ECL and D cells were performed. The six AGCH and six HDU patients were investigated again using the same tests 1 year after H. pylori eradication.

Median PAO values were no different in all the hypersecretory conditions studied. The median volume density of ECL cells in ZES was significantly higher than in controls (2.75, range 1.74-5.8 vs. 0.73, 0.52-1.11: P < 0.05), whereas it was in the control range in AGCH and HDU patients (0.77, range 0.20-1.39 and 0.99, range 0.42-1.51; respectively). The count of fundic D cells was significantly lower in AGCH patients than in all other investigated groups (median 0.16, range 0.1-0.52; P < 0.05). Cure of infection in AGCH and HDU patients did not modify the ECL cell volume density, whereas a significant increase in the count of fundic D cells was observed in AGCH patients. Thus, the ECL/D cell index was significantly affected in AGCH patients (P < 0.05), being higher during H. pylori infection (median 6, range 0.7-9.25) than after the cure (median 2.12, range 1.10-3.5). BAO and PAO were not affected by H. pylori eradication in either group.

The study provides evidence, for the first time, that quantitative alterations in the fundic endocrine cells are not involved in acid hypersecretion of patients with hypersecretory states, and that eradication of H. pylori does not restore normal acid secretion values.