Zhang Jing, Liu Suhuan, Tang Ming, Chen Jiande D Z
Veterans Research and Education Foundation, VA Medical Center, Oklahoma City, OK, United States.
Neurosci Res. 2008 Dec;62(4):262-9. doi: 10.1016/j.neures.2008.09.004. Epub 2008 Sep 26.
Gastric electric stimulation (GES) has been shown to decrease gastric tone and antrum motility, delay gastric empty, suppress appetite and induce weight loss in animal models. Our previous studies have shown that GES activates gastric-distension responsive neurons in several satiety related hypothalamic nuclei; Two hour acute GES at gastric antrum can alter the expression of anorexigenic and orexigenic peptides in the hypothalamus of rats.
To investigate the effects of GES with different stimulation parameters and locations on the neuronal expression of a hunger hormone, ghrelin and a satiety hormone, oxytocin (OT) in the hypothalamus of rats.
With immunohistochemical technique, changes in expression of satiety-related peptides-containing (OT- and ghrelin-) neurons with GES in the rodent hypothalamus were assessed. GES was performed for 2h using six different sets of parameters at three different locations.
(1) The number of ghrelin/OT-immunoreactive (IR) neurons was significantly decreased/increased with GES of the standard parameters (pulse trains: train on-time of 2s, off-time of 3s, pulse amplitude of 6 mA, width of 0.3 ms and frequency of 40 Hz) in both the paraventricular nucleus (PVN) and the superoptical nucleus (SON) compared with the control group, but not with GES of reduced pulse amplitudes, frequencies or train-on times. (2) GES with the standard parameters at the antrum resulted in a significant decrease/increase in the expression of ghrelin/OT in the PVN and the SON. However, GES at other locations (middle of lesser curvature or greater curvature) was not effective in altering the expression of ghrelin/OT.
GES with the standard parameters delivered at the distal antrum increases/decreases oxytocin/ghrelin in the hypothalamus of rats. GES with reduced parameters or delivered at the middle of the stomach is ineffective in altering these peptides.
胃电刺激（GES）已被证明在动物模型中可降低胃张力和胃窦蠕动，延迟胃排空，抑制食欲并导致体重减轻。我们之前的研究表明，GES可激活几个与饱腹感相关的下丘脑核团中对胃扩张有反应的神经元；胃窦部两小时的急性GES可改变大鼠下丘脑中厌食和促食欲肽的表达。
研究不同刺激参数和部位的GES对大鼠下丘脑饥饿激素胃饥饿素和饱腹感激素催产素（OT）神经元表达的影响。
采用免疫组织化学技术，评估啮齿动物下丘脑中含饱腹感相关肽（OT和胃饥饿素）的神经元在GES作用下的表达变化情况进行评估。在三个不同部位使用六组不同参数进行2小时的GES。
（1）与对照组相比，在室旁核（PVN）和视上核（SON）中，标准参数（脉冲序列：开启时间2秒，关闭时间3秒，脉冲幅度6毫安，宽度0.3毫秒，频率40赫兹）的GES使胃饥饿素/OT免疫反应性（IR）神经元数量显著减少/增加，但脉冲幅度、频率或开启时间降低的GES则无此效果。（2）胃窦部标准参数的GES导致PVN和SON中胃饥饿素/OT的表达显著减少/增加。然而，在其他部位（胃小弯中部或胃大弯中部）进行GES对改变胃饥饿素/OT的表达无效。
在胃远端给予标准参数的GES可增加/减少大鼠下丘脑中的催产素/胃饥饿素。参数降低或在胃中部给予的GES在改变这些肽方面无效。
