Intestinal electric stimulation accelerates whole gut transit and promotes fat excrement in conscious rats

Introduction: Intestinal electric stimulation (IES) is proposed as a potential tool for the treatment of morbid obesity. Our earlier study showed that IES with one pair of electrodes accelerated intestinal transit and decreased fat absorption in a segment of the jejunum in anesthetized rats. The aims of this study were to assess the effects of IES on whole gut transit and fat absorption in conscious rats, to examine the effects of multi-pairs IES and to explore the cholinergic mechanism behind the effects of IES. Methods: Thirty-eight male rats implanted with serosal electrodes were randomized into five groups: control without IES, two- or three-pairs IES with short pulses, atropine and atropine plus IES. The whole gut transit and fat remained and emptied from the gut were analyzed after continuous 2-h IES. Results: Two- and three-pairs IES significantly accelerated phenol red (PR, marker used for transit) excretion (analysis of variance (ANOVA), P<0.001). No significant difference was found between two- and three-pairs IES. Two-pairs IES significantly increased the excretion of fat (P<0.05). Atropine significantly blocked the accelerated transit induced by IES (ANOVA, P<0.001). Correlation was found between the percentage of PR and fat retained in the whole gut (r=0.497, P<0.01). Conclusions: IES accelerates whole gut transit and promotes fat excrement in conscious rats, and these effects are mediated through the cholinergic nerves. These findings are in support of the concept that IES may be a promising treatment option for obesity.