Ghrelin in diseases of the gastric mucosa associated with Helicobacter pylori infection

Abstract

Background: Ghrelin is a hormone produced by neuroendocrine cells of gastric mucosa. Its concentration changes in cases of Helicobacter pylori (H. pylori) infection of stomach, but the relation between the expression of plasma and mucosal ghrelin content and H. pylori infection is not completely defined. This study was designed to determine the changes in plasma and gastric mucosa ghrelin concentrations in diseases of gastric mucosa depending upon the H. pylori infection.

Material/methods: The following groups were included; Group 1. patients with gastric cancer and concomitant H. pylori infection (N=25); Group 2. patients with antral gastritis with H. pylori infection and concomitant duodenal peptic ulcer (N=18); Group 3. patients with atrophic gastritis of both the fundus and the body of the stomach without H. pylori infection (N=10); Group 4. control group consisting of patients without morphological and histological lesions of gastric mucosa and without H. pylori infection (n=25). Endoscopic biopsies of gastric mucosa of fundus, body and pyloric region were obtained in all tested groups. In patients suffering from gastric cancer biopsies of tumor were also taken. The ghrelin concentrations were measured by specific RIA. Biopsy specimens were examined to assess ghrelin mRNA expression in intact gastric mucosa and gastric cancer.

Results: The study showed significant influence of H. pylori infection on ghrelin plasma concentrations. The highest ghrelin concentrations were found in patients of the group 2 (average 503 pg/mL (95% CI: 285-886). Ghrelin concentrations were found to fall to the lowest values in the group 3 (average 144 pg/mL (95% CI: 93-222). In the group 1, the ghrelin concentration averaged 203 pg/mL (95% CI: 161-257), while in the group 4 (control group) - 255 pg/mL; 95% (CI: 160-406). The study proved that gastric cancer does not exert any ghrelin-production activity, as confirmed by RT-PCR examination of biopsy specimens of the cancer.

Conclusions: This study shows that the presence of H. pylori in the stomach with peptic ulcer increases plasma ghrelin levels, whereas in gastric cancer and atrophic gastritis it is accompanied by a marked decrease in plasma and cancer tissue levels of ghrelin.