ALTERATIONS IN GASTRIN CELLS INDUCED BY SHORT-TERM OMEPRAZOLE TREATMENT IN THE RAT ANTRUM - AN IMMUNOCYTOCHEMICAL AND IN-SITU HYBRIDIZATIONSTUDY

Gastrin is a hormonal regulator of gastric acid secretion and a trophi c stimulant of acid-producing gastric mucosa. The blockage of acid sec retion has been reported to cause hypergastrinaemia and gastrin cell h yperplasia. These findings suggest that achlorhydria may stimulate gas trin gene expression in gastrin cells. In this study, we aimed to dete rmine the alterations of gastrin mRNA by non-radioactive in situ hybri dization, and also to compare the localization of transcripts and prot ein products of the same gene by immunocytochemistry in an acid inhibi tion environment provided by omeprazole. Female Sprague-Dawley rats, w eighing 200-250 g, were divided into three groups. The first group was the control group (eight rats). The second group (eight rats) was giv en 20 mgkg(-1) day(-1) omeprazole as intragastric instillations for 4 days. The third group (eight rats) was given 100 mgkg(-1) day(-1) omep razole as in the second group. Serum gastrin levels in the two groups treated with omeprazole showed a statistically significant increase (P < 0.001) compared with the control group. The omeprazole-treated grou ps also showed an increase in the number of immunoreactive gastrin cel ls in the pyloric mucosa and an enhancement in the intensity of immuno reaction. Cells containing gastrin mRNA signals were observed in the u pper regions of the pyloric glands in the pyloric sections of the cont rol group and in both experimental groups.