Neuropeptide Y and leptin receptor expression in the hypothalamus of rats with chronic immobilization stress

In this study, Sprague-Dawley rats were immobilized to a frame for 3 hours a day for 21 days to establish a model of chronic immobilization stress. The body weight and food intake of rats subjected to chronic immobilization stress were significantly decreased compared with the control group. Dual-labeling immunofluorescence revealed that the expression of leptin receptor and the co-localization coeffient in these leptic receptor neurons in the arcuate nucleus of the hypothalamus were both upregulated, while the number of neuropeptide Y neurons was decreased. Chronic immobilization stress induced high expression of leptin receptor in the arcuate nucleus and suppressed the synthesis and secretion of neuropeptide Y, thereby disrupting the pathways in the arcuate nucleus that regulate feeding behavior, resulting in diminished food intake and reduced body weight.

Differentially Expressed Proteins in Rat Hippocampus after Chronic Immobilization Stress and Intervention Using Xiao Yao San Decoction

Objective To identify differentially expressed proteins in the hippocampus of rats after chronic immobilization stress(CIS)using a proteomics approach,and to study the effect of the Xiao Yao San(XYS)decoction on differentially expressed proteins.Methods Twenty-four Sprague Dawley rats were randomly assigned to one of four groups of equal body weight:control(non-stress),7-day stress,21-day stress and21-day stress+XYS treatment groups.Two-dimensional gel electrophoresis(2-DE)was used to detect differences in protein expression in rat hippocampus.One differentially expressed protein was measured and verified by western blotting.Results Seventeen proteins showed differential expression.Among these,eight could be identified:glial fibrillary acidic protein-2(GFAP-2),tubulin alpha-1c,cytoplasmic muscle actin2,14-3-3protein,β-2a tubulin,phosphatidylethanolamine binding protein,synucleinαsyn3,and a low molecular weight(18kD)protein.Six of these proteins exhibited increased expression,one showed decreased expression,and the other protein,which comprised five subtypes,were either increased or decreased.These proteins are known to be involved in immunity,signal transduction,cell cycle control,apoptosis,regulation of enzyme activity,cytoskeleton structure,and synaptic plasticity.GFAP-2was further analyzed,and its differential expression confirmed by western blotting.Conclusion Some proteins are differentially expressed in the hippocampus of rats under chronic stress.The biological functions of these differentially expressed proteins are varied.Finally,the XYS decoction can significantly up-or down-regulate these protein expression levels.

Comparative Study on Effects of Xiaoyao Powder and Its Modified Prescription on Plasma Metabolomics of Rats with Chronic Immobilization Stress＊

Objective： To determine the changes in the levels of endogenous metabolites in rats with chronic immobilization stress （CIS） taking Xiaoyao Powder （ XYP） and its modified prescription version, which lacks the volatile oils extracted from Herba Menthae. Methods： Twenty-four experimental male SD rats were randomly divided into 4 groups of 6 rats each： control, model, XYP-1 （containing volatile oils from Herba Menthae）, and XYP-2 （lacking volatile oils）. All rats except control group rats were subjected to CIS 3 h per day for 21 consecutive days. Groups XYP-1 and XYP-2 were given the extracted XYS with or without volatile oils （3.854 g/kg; suspended in distilled water） via gavage 1 h before CIS each day for 21 days. Rats were anesthetized using intraperitoneal injection of pentobarbital sodium （40 mg/kg） on the 22nd day. Observations were made using a Varian INOVA 600 MHz NMR spectrometer at 27 ~. Carr-PurcelI-Meiboom-Gill （CPMG） and longitudinal eddy-delay （LED） were applied, resulting in spectra showing only the signals from micro- and macro-metabolites. Results： Compared to controls, rats subjected to CIS showed increased levels of plasma metabolites, such as acetic acid, choline, N-glycoprotein （NAC）, saturated fatty acid, and blood sugars. Levels of low-density lipoprotein （LDL）, very low-density lipoprotein （VLDL）, and unsaturated fatty acids were decreased. The biochemical effects of XYS were characterized by elevated levels of VLDL, LDL, threonine, methionine, and glutamic acid in plasma. Conclusion： Some common and characteristic metabolites on the anti-CIS of XYP and its modified prescription were obtained. The metabolomics technology is a valuable tool and may be used to identify the specific metabolites and potential biomarkers of therapeutic effect of Chinese medicinal prescriptions.