Potential rat model of anxiety-like gastric hypersensitivity induced by sequential stress

AIM To establish a rat model of anxiety-like gastric hyper-sensitivity(GHS) of functional dyspepsia(FD) induced by novel sequential stress.METHODS Animal pups were divided into two groups from postnatal day 2: controls and the sequential-stress-treated. The sequential-stress-treated group received maternal separation and acute gastric irritation early in life and restraint stress in adulthood; controls were reared undisturbed with their mothers. Rats in both groups were followed to adulthood(8 wk) at which point the anxietylike behaviors and visceromotor responses to gastric distention(20-100 mm Hg) and gastric emptying were tested. Meanwhile, alterations in several anxiety-related brain-stomach modulators including 5-hydroxytryptamine(5-HT), γ-aminobutyric acid(GABA), brain-derived neurotrophic factor(BDNF) and nesfatin-1 in the rat hippocampus, plasma and gastric fundus and the 5-HT1 A receptor(5-HT1 AR) in the hippocampal CA1 subfield and the mucosa of the gastric fundus were examined.RESULTS Sequential-stress-treated rats simultaneously demonstrated anxiety-like behaviors and GHS in dose-dependent manner compared with the control group. Although rats in both groups consumed similar amount of solid food, the rate of gastric emptying was lower in the sequentialstress-treated rats than in the control group. Sequential stress significantly decreased the levels of 5-HT(51.91 ± 1.88 vs 104.21 ± 2.88, P < 0.01), GABA(2.38 ± 0.16 vs 5.01 ± 0.13, P < 0.01) and BDNF(304.40 ± 10.16 vs 698.17 ± 27.91, P < 0.01) in the hippocampus but increased the content of nesfatin-1(1961.38 ± 56.89 vs 1007.50 ± 33.05, P < 0.01) in the same site; significantly decreased the levels of 5-HT(47.82 ± 2.29 vs 89.45 ± 2.61, P < 0.01) and BDNF(257.05 ± 12.89 vs 536.71 ± 20.73, P < 0.01) in the plasma but increased the content of nesfatin-1 in it(1391.75 ± 42.77 vs 737.88 ± 33.15, P < 0.01); significantly decreased the levels of 5-HT(41.15 ± 1.81 vs 89.17 ± 2.31, P < 0.01) and BDNF(226.49 ± 12.10 vs 551.36 ± 16.47, P < 0.01) in the gastric fundus but increased the content of nesfatin-1 in the same site(1534.75 ± 38.52 vs 819.63 ± 38.04, P < 0.01). The expressions of 5-HT1 AR in the hippocampal CA1 subfield and the mucosa of the gastric fundus were down-regulated measured by IHC(Optical Density value: Hippocampus 15253.50 ± 760.35 vs 21149.75 ± 834.13; gastric fundus 15865.25 ± 521.24 vs 23865.75 ± 1868.60; P < 0.05, respectively) and WB(0.38 ± 0.01 vs 0.57 ± 0.03, P < 0.01)(n = 8 in each group). CONCLUSION Sequential stress could induce a potential rat model of anxiety-like GHS of FD, which could be used to research the mechanisms of this intractable disease.

Rapid Determination of Dopamine and Its Metabolites During in vivo Cerebral Microdialysis by Routine High Performance Liquid Chromatography With Electrochemical Detection

Objective To determine dopamine and its metabolites during in vivo cerebral microdialysis by routine high performance liquid chromatography with electrochemical detection.Methods Microdialysis probes were placed into the right striatum of Wistar rat brains and perfused with Ringer's solution at a rate of 1.5 μL/min.A reverse phase HPLC with electrochemistry was used to assay DA,DOPAC,and HVA after cerebral microdialysates were collected every 20 minutes from awake and freely moving rats.In order to identify the reliability of this method,its selectivity,linear range,precision and accuracy were tested and the contents of DA,DOPAC,and HVA in rat microdialysates were determined.Results The standard curve was in good linear at the concentration ranging from 74 nmol/L to 1.5 μmol/L for DOPAC(r2= 0.9996),from 66 nmol/L to 1.3 μmol/L for DA(r2=1.0000)and from 69 nmol/L to 1.4 μmol/L for HVA(r2=0.9992).The recovery of DOPAC(0.30,0.77,1.49 μmol/L),DA(0.26,0.69,1.32 μmol/L),and HVA(0.27,0.71,1.37 μmol/L)was 82.00±1.70%,104.00±4.00%,98.70±3.10%;92.30±1.50%,105.30±2.30%,108.00±2.00%;80.00±7.80%,107.69±8.00%,and 108.66±3.10%,respectively at each concentration.Their intra-day RSD was 3.3%,3.4%,and 2.5%,and inter-day RSD was 4.2%,2.3%,and 5.6%,respectively.The mean extracellular concentrations of DOPAC,DA,and HVA in rat brain microdialysates were 10.7,2.4,and 9.2 μmol/L(n=6),respectively.Conclusion The findings of our study suggested that the simple,accurate and stable method can be applied to basic researches of diseases related to monoamines neurotransmitters by cerebral microdialysis in rats.

24小时食管多通道腔内阻抗-pH监测阳性的113例胃食管反流病(GERD)患者的胃食管反流特点（英文）

目的:通过分析多通道腔内阻抗-pH监测(MII-pH)阳性的胃食管反流病(GERD)患者的各项反流指标,探讨我国GERD患者的胃食管反流特点,以及性别、年龄、体位和体质指数(BMI)对反流的影响。创新点:入组患者均经MII-pH监测证实具有客观存在的胃食管反流,分析体位和BMI对反流的影响,并且发现我国GERD患者普遍存在弱酸反流。方法:有典型反流症状的疑诊GERD患者,进行24 h MII-pH监测,对监测结果阳性的患者纳入研究对象,分析其各反流指标以及性别、年龄、体位和BMI对反流的影响。结论:我国GERD患者普遍存在弱酸反流,男性、直立体位、肥胖(BMI≥25)可促进胃食管反流的发生,且年龄不是胃食管反流的危险因素。