Date Published: March 28, 2017
Publisher: Public Library of Science
Author(s): Jingzhu Zhou, Shiying Li, Yinping Wang, Yong Lei, Robert D. Foreman, Jieyun Yin, Jiande D. Z. Chen, Yvette Tache.
Functional dyspepsia (FD) is a common functional gastrointestinal disease, and abdominal pain is one of the main symptoms. The aim of this study was to explore the effects and mechanisms of auricular electro-acupuncture (AEA) on gastric hypersensitivity in a rodent model of FD.
Ten-day-old pups were gavaged with 0.2 ml of 0.1% iodoacetamide daily for 6 days. AEA at the “stomach” point with different parameters or sham-EA was performed on 8-week-old animals. Gastric sensitivity to gastric distention was measured under different conditions. Autonomic functions were assessed from the spectral analysis of heart rate variability (HRV) derived from the electrocardiogram. Naloxone was injected intraperitoneally before AEA to explore the opioid mechanism. Gastric emptying was measured at the end of the study.
1) Gastric sensitivity to gastric distention was higher in the FD rats. AEA with parameters of 0.1s on, 0.4s off, 100Hz, 0.3ms and 0.4–0.5mA, but not other parameters or sham-EA, decreased gastric hypersensitivity in the FD rats. Naloxone did not block the effect of AEA. 2) Lower vagal activity and higher sympathovagal ratio were noted in the FD rats, compared with the controls. AEA increased vagal activity and improved sympathovagal imbalance.
AEA ameliorates gastric hypersensitivity in FD rats and this effect may be attributed to the improvement of sympathovagal balance.
Functional dyspepsia (FD) is one of functional gastrointestinal diseases with major complaints of postprandial fullness, early satiety, epigastric pain and burning sensation. The prevalence of FD ranges from 11.5%-29.2% worldwide . Epigastric pain is one of dominating reasons for a FD patient to seek medical help. The cost of FD in 2009 was evaluated up to $18.4 billion in USA . However, the treatment for FD is limited and unsatisfactory. Helicobacter pylori eradication is suggested if helicobacter pylori infection exists . Proton pump inhibitors, prokinetics, antidepressants and serotonin reuptake inhibitors are used to relieve symptoms [4, 5].
In this study, we found that AEA with proper parameters decreased gastric hypersensitivity in FD rats without altering gastric emptying. This ameliorating effect of AEA might be mediated via the regulation of abnormal autonomic functions in FD rats. Naloxone did not block the ameliorating effect of AEA on gastric hypersensitivity in FD rats, excluding the involvement of the opioid pathway.