Chronic gastric electrical stimulation leads to weight loss via modulating multiple tissue neuropeptide Y, orexin, α-melanocyte-stimulating hormone and oxytocin in obese rats

<b><i>Objectives. </i></b>Gastric electrical stimulation (GES) has great potential for the treatment of obesity. We investigated the impact of chronic GES on the alteration of adipose tissue and the regulation of neuropeptide Y (NPY), orexin (OX), α-melanocyte-stimulating hormone (α-MSH) and oxytocin (OXT), and their receptors in several tissues. <b><i>Material and methods.</i></b> Most of the experiments included three groups of diet-induced obesity rats: (1) sham-GES (SGES); (2) GL-6mA (GES with 6 mA, 4 ms, 40 Hz, 2 s on, 3 s off at lesser curvature); and (3) SGES-PF (SGES rats receiving pair feeding to match the consumption of GL-6mA rats). Chronic GES was applied for 2 h every day for 4 weeks. During treatment with GES, food intake and body weight were monitored weekly. The alteration of epididymal fat weight, gastric emptying, and expression of peptides and their receptors in several tissues were determined. <b><i>Results.</i></b> GL-6mA was more potent than SGES-PF in decreasing body weight gain, epididymal fat tissue weight, adipocyte size and gastric emptying. Chronic GES significantly altered NPY, OX, α-MSH and OXT and their receptors in the hypothalamus, adipose tissue and stomach. <b><i>Conclusions. </i></b>Chronic GES effectively leads to weight loss by reducing food intake, fat tissue weight and gastric emptying. NPY, α-MSH, orexin and OXT, and their receptors in the hypothalamus, adipose tissue and stomach appear to be involved in the anti-obesity effects of chronic GES.