【Animal Modeling】-Exploring the effect of stress on appetite in rats from the brain-stomach ghrelin pathway

  Objective To study the molecular mechanism of stress affecting appetite from the brain ghrelin pathway.

  Methods Thirty-two male Wistar rats were randomly divided into control group and stress group, with 16 rats in each group and 2 rats in each cage. The rats were stimulated by the method of tail clipping twice a day for 21 consecutive days, and the food intake and body weight of the rats in each group were monitored; on the 7th and 21st days of the experiment, 8 rats in each group were selected, and the serum was detected by ELISA. The mass concentration of acylated ghrelin; Western blotting was used to detect the expression of ghrelin protein in the stomach and hypothalamus of rats, as well as the expression level of Amp-activated protein kinase α2 (AMPKα2) in the hypothalamus; Real-time fluorescence quantitative PCR detection Ghrelin, growth hormone secretagogue receptor (GHSR), leptin in stomach, and ghrelin, AMPKo2, neuropeptide Y (NPY), agouti gene-related protein ( agouti-related protein, AgRP) mRNA levels.

  Results On the 7th day of the experiment, the total food intake per cage of the rats in the stress group was more than that in the control group (P<0.05). 21="" there="" was="" no="" significant="" difference="" in="" the="" body="" weight="" of="" two="" groups="" rats="" p="">0.05). Stress can significantly up-regulate the level of acylated ghrelin in serum (P<0.01), the expression of ghrelin protein in stomach and hypothalamus (P<0.05) and AMPKg2 protein in hypothalamus (P<0.01) were also significantly up-regulated. Stress can also significantly up-regulate the levels of ghrelin and GHSR mRNA in the stomach (P<0.01), down-regulate the level of leptin mRNA in the stomach (P<0.01), and up-regulate the mRNA levels of ghrelin, AMPKα2, NPY and AgRP in the hypothalamus (P≤0.01). .

  Conclusion Tail clipping stress can lead to the up-regulation of central and peripheral ghrelin levels in rats, which may have an effect on the temporary increase of appetite in rats.