Expression Of Gastrointestinal Nesfatin-1and Gastric Emptying In VMH-and VLH-lesioned Rats

Background Nesfatin-1was originally identified as a hypothalamic neuropeptide derived from nucleobindin-2(NUCB2) that exhibits the ability to suppress food intake. In addition to its central anorexigenic activity, the expression patterns of NUCB2/nesfatin-1in peripheral tissues, such as adipose and serum, were recently reported. However, it is not known whether gastrointestinal nesfatin-1is correlated with energy balance and gastric mobility. In the present study, our aim was to determine the expression levels of gastrointestinal nesfatin-1in VMH-lesioned (obese) and VLH-lesioned (lean) rats that exhibit an imbalance in their energy metabolism and gastric mobility.Methods Male Wistar rats were randomly divided into the ventromedial nuclei (VMH)-lesioned, ventrolateral nuclei (VLH)-lesioned, and their respective sham-operated groups. Bilateral VMH and VLH were produced by passing an anodal direct current (2mA for10s), while the control animals received sham lesions (no current was passed through the electrode). The animals had free access to food and water, and their diets and weights were monitored after surgery.At the end of21days, gastric emptying was assessed through a modified phenol red-methylcellulose recovery method.The stomach, duodenum, small intestine and colon were collected to detect the expression of NUCB2mRNA and nesfatin-1immunoreactive (IR) cells by real-time RT-PCR, immunohistochemical and fluorescent staining, respectively. Comparison between two groups was done with independent sample T-test, and RT-PCR were analysed by using rest2009softweare.Results Our observations indicated that the VMH-lesioned rats fed normal chow exhibited markedly greater food intake and body weight gain, whereas the VLH-lesioned rats exhibited markedly lower food intake and body weight gain. Compared with their respective controls, gastric emptying was enhanced in the VMH-lesioned rats (85.94±2.27%), whereas the VLH lesions exhibited inhibitory effects on gastric emptying (29.12±1.62%).NUCB2/nesfatin-1IR cells were localised in the lower third and middle portion of the gastric mucosal gland and in the submucous layer of the enteric tract. In the VMH-lesioned rats, the levels of NUCB2mRNA and nesfatin-1protein were significantly increased in the stomach and duodenum and reduced in the small intestine. In addition, the levels of NUCB2mRNA and nesfatin-1protein in the VLH-lesioned rats were decreased in the stomach, duodenum, and small intestine.Conclusions Our study demonstrated that nesfatin-1level in the stomach and duodenum is positively correlated with body mass. Additionally, there is also a positive relationship between gastric emptying and body mass. The results of this study indicate that gastrointestinal nesfatin-1may play a significant role in gastric mobility and energy homeostasis.