Inhibitory effect of somatostatin on Helicobacter pylori proliferation in vitro

Gastroenterology. 1998 Nov;115(5):1123-30. doi: 10.1016/s0016-5085(98)70083-6.


Background & aims: Somatostatin regulates gastric function and cell proliferation. We investigated whether exogenous somatostatin modulates Helicobacter pylori proliferation in vitro.

Methods: Bacteria were cultured in 5 mL Brucella broth. Bacterial numbers of H. pylori (ATCC 43504) and Escherichia coli were calculated 48 and 5 hours after incubation, respectively, by counting the colonies on the blood agar. Chemicals were dissolved in absolute methanol and added to the broth at a final methanol concentration of 1%. Intrabacterial guanosine 3',5'-cyclic monophosphate (cGMP) and adenosine 3',5'-cyclic monophosphate (cAMP) levels were measured by radioimmunoassay.

Results: Somatostatin significantly suppressed H. pylori proliferation at levels at or above 10(-11) mol/L. A similar antiproliferative effect was observed with 8-bromo-cGMP. At concentrations at or above 10(-8) mol/L, dibutyryl cAMP slightly but significantly stimulated bacterial proliferation. Gastrin had no effect. Somatostatin antibody immunoglobulin G fraction blocked the antiproliferative effect of somatostatin on ATCC 43504. Scatchard plot showed that ATCC 43504 has one class of binding site with relatively high affinity (Kd, 0.31 nmol/L). Somatostatin at 10(-11) mol/L increased cGMP and cAMP in H. pylori 11-fold and 6-fold, respectively. In contrast, somatostatin neither bound E. coli nor affected its proliferation.

Conclusions: Somatostatin, at a similar level in human gastric juice (approximately 10(-11) mol/L), suppresses H. pylori proliferation mediated in part by a cGMP-dependent pathway in vitro, indicating a possible inhibitory effect of somatostatin in the gastric lumen on H. pylori proliferation in humans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies / immunology
  • Bacterial Proteins / metabolism
  • Cell Division / drug effects
  • Cyclic AMP / metabolism
  • Cyclic GMP / metabolism
  • Dose-Response Relationship, Drug
  • Helicobacter pylori / cytology*
  • Helicobacter pylori / drug effects*
  • Helicobacter pylori / metabolism
  • In Vitro Techniques
  • Somatostatin / immunology
  • Somatostatin / pharmacology*


  • Antibodies
  • Bacterial Proteins
  • Somatostatin
  • Cyclic AMP
  • Cyclic GMP