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.

<b><i>研究目的。</i></b> 胃电刺激（Gastric electrical stimulation, GES）在肥胖症治疗中具有巨大应用潜力。本研究探讨慢性胃电刺激对脂肪组织的调控作用，以及其对多种组织中神经肽Y（NPY）、食欲素（OX）、α-黑素细胞刺激素（α-MSH）与催产素（OXT）及其受体表达的影响。<b><i>材料与方法。</i></b> 本研究多数实验纳入三组饮食诱导肥胖大鼠：(1) 假手术胃电刺激组（sham-GES）；(2) GL-6mA组（于胃小弯处施加参数为6 mA、4 ms、40 Hz，2秒开启、3秒关闭的胃电刺激）；(3) 配对喂养假手术组（SGES-PF，即接受配对喂养以匹配GL-6mA组大鼠进食量的假手术胃电刺激大鼠）。慢性胃电刺激每日干预2小时，持续4周。胃电刺激干预期间，每周监测大鼠进食量与体重。本研究同时检测了各组大鼠的附睾脂肪重量、胃排空功能，以及多种组织中肽类及其受体的表达变化。<b><i>研究结果。</i></b> GL-6mA组在降低体重增重、附睾脂肪组织重量、脂肪细胞体积及改善胃排空方面，效果优于SGES-PF组。慢性胃电刺激可显著改变下丘脑、脂肪组织与胃组织中NPY、OX、α-MSH及OXT及其受体的表达水平。<b><i>研究结论。</i></b> 慢性胃电刺激可通过减少进食量、降低脂肪组织重量与改善胃排空，有效实现减重效果。下丘脑、脂肪组织与胃组织中的NPY、α-MSH、食欲素及催产素及其受体，似乎参与了慢性胃电刺激的抗肥胖作用机制。