The aim of the study was to evaluate the therapeutic value and possible mechanisms of transcutaneous electroacupuncture (TEA) in a double-blind and cross-over study in patients with functional dyspepsia (FD). Twenty-seven patients with FD were enrolled and the study consisted of two parts: (i) acute effects of TEA at PC6 and ST36 on gastric slow waves and heart rate variability and (ii) chronic (2 weeks) effects of TEA at PC6 and ST36 on dyspepsia symptoms, gastric slow waves, heart rate variability and neuropeptide Y (NPY) and motilin. The results of this study are: (i) The dyspepsia symptom score was decreased by 55% at the end of chronic TEA and the improvement was significant (P < 0.01); (ii) the high frequency (HF) assessed from the spectral analysis of heart rate variability was markedly increased with both acute TEA (76% increase, P = 0.01) and chronic TEA (75% increase, P = 0.025); (iii) gastric slow waves were not altered by either acute or chronic TEA; and (iv) the plasma level of NPY but not motilin was increased after chronic TEA. Non-invasive and needleless transcutaenous electroacupuncture at ST36 and PC6 markedly improves dyspepsia symptoms and the improvement may be associated with the increase in HF heart rate variability and the modulation of NPY.

Gastric electrical stimulation (GES) has been applied to treat gastroparesis and morbid obesity. The aims of this study were to evaluate the sites of stimulation and the mechanisms of GES on gastric tone and accommodation. Gastric tone and accommodation were evaluated with a barostat in surgically prepared dogs. GES was applied at seven different locations, and gastric tone was assessed at each site. The effect of truncal vagotomy on gastric tone and accommodation and the role of the nitrergic pathway were also evaluated. We have found: 1) GES induced varying degrees of gastric relaxation at all tested locations in normal dogs; 2) Gastric volume was also significantly increased with GES in vagotomized dogs and the change tended to be lower than that of normal animals; 3) Gastric accommodation was reduced during GES in both the normal and vagotomized dogs and the reduction tended to be more in the vagotomized animals; 4) The GES-induced increase in gastric volume was partially abolished by intravenous nitric oxide synthase inhibitor. GES at various sites of the stomach exerts inhibitory effect on gastric tone; the most effective sites are in the antrum along the lesser or greater curvature; the inhibitory effect of GES on gastric tone is partially mediated by the vagal and nitrergic pathway.

GES activates gastric-related neurons in the PVN, and the excitatory effect of GES seems related to stimulation strength. The GES used for treating gastroparesis and the GES used for treating obesity seem to solicit different neuronal responses in the PVN.

It was concluded that enhanced viscosity delays gastric emptying, increases postprandial intestinal but not gastric motility, and has no effects on gastric or intestinal slow waves.