脑源性神经营养因子在结肠炎后内脏高敏感小鼠中的调节作用

背景：脑源性神经营养因子（BDNF）可调控突触可塑性和维持神经内环境的稳定,近年研究证实BDNF参与痛觉的调控。目的：研究BDNF在结肠炎后内脏高敏感小鼠中的调节作用。方法：以结肠内灌注三硝基苯磺酸（TNBS）诱导建立结肠炎后内脏高敏感模型。将小鼠分为BDNF＋/＋对照组、BDNF＋/＋TNBS炎症组、BDNF＋/-对照组和BDNF＋/-TNBS炎症组。行结肠和膀胱组织学检查,以ELISA法测定背根神经节内BDNF蛋白表达,记录各组对结直肠扩张的反应和膀胱敏感性。结果：TNBS对两种基因型小鼠均可诱导明显的结肠炎症。同一基因型小鼠TNBS炎症组背根神经节BDNF表达显著高于相应对照组（P〈0.05）,同时伴有结肠和膀胱敏感性上调（P〈0.05）。BDNF＋/-TNBS炎症组和对照组BDNF表达分别显著低于相应BDNF＋/＋小鼠（P〈0.05）,BDNF＋/-TNBS炎症小鼠的结肠和膀胱敏感性显著低于BDNF＋/＋TNBS炎症小鼠（P〈0.05）。除结直肠扩张压力≥60 mm Hg外,BDNF＋/-对照小鼠的结肠和膀胱敏感性与BDNF＋/＋对照小鼠无明显差异。结论：BDNF对结肠炎后结肠高敏感和牵涉性膀胱高敏感具有调节作用。

Role of Brain-derived Neurotrophic Factor in the Modulation of Post-inflammatory Visceral Hypersensitivity in Mice

Background: Brain-derived neurotrophic factor(BDNF) can modulate the plasticity of synapses and maintain the environment of nervous system.Recent studies show that BDNF is also involved in pain modulation.Aims: To investigate the role of BDNF in the modulation of post-inflammatory visceral hypersensitivity in mice.Methods: Colitis model was induced in mice by enema with 2,4,6-trinitrobenzene sulfonic acid(TNBS).BDNF+/+ and BDNF+/- mice were divided into BDNF+/+ control group,BDNF+/+ TNBS-colitis group,BDNF+/- control group and BDNF+/- TNBS-colitis group.Histology examination of colon and bladder was performed.Expression of BDNF in dorsal root ganglia was determined by ELISA.Visceral response to colorectal distension and bladder sensitivity were recorded.Results: Colitis was successfully induced by TNBS in both genotypes mice.Expression of BDNF in dorsal root ganglia was significantly higher in both TNBS-colitis groups than that in corresponding control groups(P<0.05),and sensitivity of colon and bladder was up-regulated(P<0.05).Expression of BDNF in BDNF+/- TNBS-colitis group and BDNF+/- control group was significantly lower than that in BDNF+/+ TNBS-colitis group and BDNF+/+ control group,respectively(P<0.05).Sensitivity of colon and bladder in BDNF+/- TNBS-colitis group was significantly lower than that in BDNF+/+ TNBS-colitis group(P<0.05),while no significant difference was found between BDNF+/- control group and BDNF+/+ control group except with colorectal distention ≥ 60 mm Hg.Conclusions: BDNF participates in the modulation of post-inflammatory colonic and referred bladder hypersensitivity.