Psychological stress enhances the colonization of the stomach by Helicobacter pylori in the BALB/c mouse

Abstract

Helicobacter pylori infection is a risk factor for development of peptic ulcers, and psychological stress (PS) may have a role in the pathogenesis of this condition. However, no interaction between PS and H. pylori infection (HI) has been established in the development of peptic ulcer, because colonization by H. pylori is the first step in the infection of the gastric mucosa, we examined H. pylori colonization of the stomach in BALB/c mice after PS. The mice were subjected to PS in a communication box test, in which they observed other mice experiencing a physical stressor (electrical) before they were inoculated with H. pylori. We found that the H. pylori colonization in the stomach of psychologically stressed mice was significantly greater than in the control mice (P < 0.05), and histological examination showed that the gastric mucosal injury in the stressed mice was more extensive than in the control mice (P < 0.05). To explore the underlying mechanisms, we administered RU486 (a type II glucocorticoid (GC) receptor antagonist) to antagonize the effect of endogenous corticosterone: this treatment decreased colonization by H. pylori in the psychologically stressed mice. We conclude that HI of the stomach of BALB/c mice is enhanced by PS, and the effect may be mediated by GCs.

Keywords::

• Corticosterone
• Helicobacter pylori
• peptic ulcer
• psychological stress
• real-time PCR
• RU486

Acknowledgements

This work was supported by grants from the National Basic Research Program of China (No. 2009CB522606). We would like to thank Professor Min Li (Department of Psychology, Third Military Medical University), Associate Professor Bang-Yun Zhao (Department of Physiology, Third Military Medical University), for the design of experiments and the animal model, and post-graduate Li-Qiang Zhu (Department of Health Statistics, Third Military Medical University), for assistance with statistical analysis.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.