Skip to main content
NCBI home page
Gut logoLink to Gut
. 1996 Jan;38(1):6–10. doi: 10.1136/gut.38.1.6

Omeprazole promotes proximal duodenal mucosal bicarbonate secretion in humans.

A Mertz-Nielsen 1, J Hillingsø 1, K Bukhave 1, J Rask-Madsen 1
PMCID: PMC1382970  PMID: 8566861

Abstract

The proton pump inhibitor, omeprazole, surprisingly resulted in higher rates of proximal duodenal mucosal bicarbonate secretion than previously reported using an H2 receptor antagonist for gastric acid inhibition. Gastroduodenal perfusions were performed in healthy volunteers to evaluate whether this incidental finding is explained by more potent gastric acid inhibition by omeprazole or might be caused by the different mode of drug action. Basal and stimulated gastric and duodenal bicarbonate secretion rates were measured in the same subjects in control experiments (n = 17) and after pretreatment with high dose omeprazole (n = 17) and ranitidine (n = 9), respectively, by use of a technique permitting simultaneous measurements. Concentrations of bicarbonate were measured in the respective effluents by the method of back titration. Both omeprazole and ranitidine completely inhibited gastric acid secretion (pH 6.9 v 6.8; p > 0.05). Omeprazole caused higher rates of basal (mean (SEM)) (597 (48) v 351 (39) mumol/h; p < 0.02) and vagally stimulated (834 (72) v 474 (66) mumol/h; p < 0.02), but not acid stimulated (3351 (678) v 2550 (456) mumol/h; p > 0.05) duodenal bicarbonate secretion compared with control experiments. Also the combination of omeprazole and ranitidine increased (p = 0.05) duodenal bicarbonate secretion, while ranitidine alone caused no change in either basal or stimulated secretion. In the stomach basal as well as vagally stimulated bicarbonate secretion was independent of the means of acid inhibition. These results show that the proton pump inhibitor, omeprazole, promotes proximal duodenal mucosal bicarbonate secretion apparently independent of its gastric acid inhibitory effect. The mechanism of action remains speculative.

Full text

PDF
6

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Ainsworth M. A., Kjeldsen J., Schaffalitzky de Muckadell O. B. Morphine inhibits secretion of bicarbonate from the human duodenal mucosa. Possible role of endogenous opioids in the regulation of human duodenal mucosal bicarbonate secretion. Scand J Gastroenterol. 1990 Oct;25(10):1066–1075. doi: 10.3109/00365529008997636. [DOI] [PubMed] [Google Scholar]
  2. Carrick J., Lee A., Hazell S., Ralston M., Daskalopoulos G. Campylobacter pylori, duodenal ulcer, and gastric metaplasia: possible role of functional heterotopic tissue in ulcerogenesis. Gut. 1989 Jun;30(6):790–797. doi: 10.1136/gut.30.6.790. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Flemström G., Kivilaakso E. Demonstration of a pH gradient at the luminal surface of rat duodenum in vivo and its dependence on mucosal alkaline secretion. Gastroenterology. 1983 Apr;84(4):787–794. [PubMed] [Google Scholar]
  4. Forssell H., Stenquist B., Olbe L. Vagal stimulation of human gastric bicarbonate secretion. Gastroenterology. 1985 Sep;89(3):581–586. doi: 10.1016/0016-5085(85)90454-8. [DOI] [PubMed] [Google Scholar]
  5. Fändriks L., Jönson C. Effects of acute administration of omeprazole or ranitidine on basal and vagally stimulated gastric acid secretion and alkalinization of the duodenum in anaesthetized cats. Acta Physiol Scand. 1990 Feb;138(2):181–186. doi: 10.1111/j.1748-1716.1990.tb08831.x. [DOI] [PubMed] [Google Scholar]
  6. Fändriks L., Stage L. Simultaneous measurements of gastric motility and acid-bicarbonate secretions in the anaesthetized cat. Acta Physiol Scand. 1986 Dec;128(4):563–573. doi: 10.1111/j.1748-1716.1986.tb08013.x. [DOI] [PubMed] [Google Scholar]
  7. Guslandi M. Alkali secretion by the human stomach: effect of H2 blockers. Am J Physiol. 1985 Nov;249(5 Pt 1):G649–G649. doi: 10.1152/ajpgi.1985.249.5.G649. [DOI] [PubMed] [Google Scholar]
  8. Guttu K., Røsok B., Gislason H., Fändriks L., Svanes K., Grønbech J. E. Gastric bicarbonate secretion, acid secretion, and mucosal blood flow during influence of pentagastrin and omeprazole in the cat. Scand J Gastroenterol. 1991 Apr;26(4):431–441. doi: 10.3109/00365529108996506. [DOI] [PubMed] [Google Scholar]
  9. Knutson L., Flemström G. Duodenal mucosal bicarbonate secretion in man. Stimulation by acid and inhibition by the alpha 2-adrenoceptor agonist clonidine. Gut. 1989 Dec;30(12):1708–1715. doi: 10.1136/gut.30.12.1708. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Knutson L., Flemström G., Gustavsson S., Jedstedt G., Lönnerholm G. HCO3- secretion in rat duodenum after treatment with omeprazole and ranitidine. Scand J Gastroenterol. 1987 Jan;22(1):87–90. doi: 10.3109/00365528708991862. [DOI] [PubMed] [Google Scholar]
  11. McTavish D., Buckley M. M., Heel R. C. Omeprazole. An updated review of its pharmacology and therapeutic use in acid-related disorders. Drugs. 1991 Jul;42(1):138–170. doi: 10.2165/00003495-199142010-00008. [DOI] [PubMed] [Google Scholar]
  12. Mertz-Nielsen A., Eskerod O., Bukhave K., Rask-Madsen J. Misoprostol inhibits gastric mucosal release of endogenous prostaglandin E2 and thromboxane B2 in healthy volunteers. Gut. 1995 Apr;36(4):511–515. doi: 10.1136/gut.36.4.511. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Mertz-Nielsen A., Hillingsø J., Eskerod O., Bukhave K., Rask-Madsen J. Muscarinic M1 receptor inhibition reduces gastroduodenal bicarbonate secretion and promotes gastric prostaglandin E2 synthesis in healthy volunteers. Gut. 1995 Apr;36(4):528–533. doi: 10.1136/gut.36.4.528. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Noach L. A., Rolf T. M., Bosma N. B., Schwartz M. P., Oosting J., Rauws E. A., Tytgat G. N. Gastric metaplasia and Helicobacter pylori infection. Gut. 1993 Nov;34(11):1510–1514. doi: 10.1136/gut.34.11.1510. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Odes H. S., Hogan D. L., Steinbach J. H., Ballesteros M. A., Koss M. A., Isenberg J. I. Measurement of gastric bicarbonate secretion in the human stomach: different methods produce discordant results. Scand J Gastroenterol. 1992 Oct;27(10):829–836. doi: 10.3109/00365529209000149. [DOI] [PubMed] [Google Scholar]
  16. Takeuchi K., Magee D., Critchlow J., Matthews J., Silen W. Studies of the pH gradient and thickness of frog gastric mucus gel. Gastroenterology. 1983 Feb;84(2):331–340. [PubMed] [Google Scholar]
  17. White J. F. Omeprazole inhibits H+ secretion by Amphiuma jejunum. Am J Physiol. 1985 Feb;248(2 Pt 1):G256–G259. doi: 10.1152/ajpgi.1985.248.2.G256. [DOI] [PubMed] [Google Scholar]

Articles from Gut are provided here courtesy of BMJ Publishing Group

RESOURCES