EFFECT OF OMEPRAZOLE ON REGULATION OF ANTRAL SOMATOSTATIN IN HUMAN-BEINGS

Omeprazole, a proton pump inhibitor, suppresses gastric acid secretion thereby producing gastrin hypersecretion. Using omeprazole we studied the regulation of antral somatostatin. Five subjects ingested 20 mg o f omeprazole each and seven others took 40 mg each, all for a period o f eight days. Both types of treatment significantly increased basal se rum gastrin levels, but we observed no significant difference between the results effected by the two dosages. Subjects who ingested 40 mg/d ay of omeprazole experienced a significant decrease of antral somatost atin content, while the five who took only 20 mg/day did not. Antral s omatostatin mRNA levels were found unchanged following both forms of t reatment. These results indicate that antral somatostatin might be one of the factors that cause gastrin hypersecretion by administration of omeprazole.