Effects of acid inhibition on somatostatin-producing cells in the rat gastric fundus

Somatostatin plays a role in the regulation of gastric acid secretion. Omep razole, a potent inhibitor of gastric acid secretion, has been reported to cause either a significant decrease or increase in the formation of gastric somatostatin-producing cells. Therefore, we determined in the present stud y distribution patterns of somatostatin mRNA and protein in fundus mucosa o f rats after long-term inhibition of gastric acid secretion. Female Sprague -Dawley rats were given 0, 20 and 100 mg/kg/day omeprazole, respectively, a s gastric instillations during 2 months. Serum gastrin levels were signific antly higher in the third group than in the other groups. The omeprazole-tr eated groups also showed an increase in the number of somatostatin-containi ng cells in fundus mucosa. Moreover, the intensity of somatostatin-positivi ty was higher in the treated groups than in the control group. We also obse rved an increase in the number of cells containing somatostatin mRNA. in fu ndus mucosa of omeprazole-treated rats. These results suggest that long-ter m inhibition of acid secretion does not inhibit but stimulate somatostatin production in mucosa of rat gastric fundus.