Effects of proximal gastric electrical stimulation on feeding behavior and gastrointestinal function in rats

Objective To observe the effects of proximal gastric electrical stimulation (GES) on body weight and gastrointestinal motility in SD rats, and investigate the regulation of gastric nerve stimulation and serum gastrointestinal hormones by neuro-humoral regulation. Methods 12 SD rats were divided into experimental group (n=6) and control group (n=6), with gastric electrical stimulator implanted, and in experimental group dual-channel GES was activated. General status was observed for 4 weeks after GES activation, including body weight, feeding and water intake, urine and stool volumes, the resting gastric volume and gastric emptying were monitored via the establishment of intestinal fistula, and serum gastrointestinal hormones change was detected. Results During 4-week GES process, one rat had gastric retention and died at 1 week after GES activated. Compared with the control group, body weight, food intake, urine and stool volumes levels of the rats in experimental group decreased significantly (t=4.005, 2.530, 3.350, all P<0.05). Resting gastric volume was significantly lower than that in the control group [(2.93±0.50)ml vs.(5.10±0.53)ml, Z=2.460, P=0.014], and the intestinal juice drainage was lower than the control group [(0.18±0.15)ml vs.(0.44±0.05)ml, Z=2.513, P=0.012], while serum GLP-1 levels were similar between the two groups [(0.44±0.05)ml vs.(0.18±0.15)ml, Z=1.026, P=0.305], but Ghrelin was significantly higher than that in the control group [(1.65±0.58) vs. (0.65±0.36), Z=2.380, P=0.017]. Conclusion The proximal GES may lead to the change of the body weight, food intake, gastrointestinal function and motility, possibly by stimulating nerve reflex inducing gastrointestinal hormones secretion and affect gastrointestinal function. Key words: Electrical stimulation; Gastrointestinal hormones; Gastric emptying