摘要：

目的 探讨颅脑创伤后期（第7 天）大鼠脑组织代谢型谷氨酸受体5（mGluR5）表达变化，以及牛磺酸治疗作用。方法 液压脑损伤打击仪制备液压打击颅脑创伤大鼠模型，采用随机数字表法将30 只无特定病原体级Sprague-Dawley 大鼠随机分为对照组、颅脑创伤组和牛磺酸治疗组（各10 只），干湿重法检测大鼠脑组织含水量，实时荧光定量聚合酶链反应和Western blotting 法检测水通道蛋白4（AQP4）和mGluR5 mRNA 和蛋白表达变化。结果 与对照组相比，颅脑创伤组大鼠脑组织含水量（t = 4.893，P = 0.002）、AQP4 mRNA（t = 6.523，P = 0.000）和蛋白（t = 4.366，P = 0.008）表达水平升高，mGluR5 mRNA（t = 5.776，P = 0.001）和蛋白（t = 3.945，P = 0.014）表达水平降低；经牛磺酸治疗后，大鼠脑组织含水量（t = 2.151，P = 0.140）、AQP4 mRNA（t = 1.144，P = 0.432）和蛋白（t = 0.367，P = 0.804）降至正常水平，mGluR5 mRNA（t = 1.824，P = 0.216）和蛋白（t = 1.185，P = 0.414）升至正常水平。相关分析显示，脑组织含水量与mGluR5 mRNA（r = -0.617，P = 0.014）和蛋白（r = -0.665，P = 0.007）呈负相关，与AQP4蛋白呈正相关（r = 0.658，P = 0.008）。结论 牛磺酸可以升高颅脑创伤后期（第7 天）大鼠脑组织mGluR5 表达水平，降低脑水肿和脑组织含水量，具有抑制性神经递质作用。

关键词: 颅脑损伤, 受体, 谷氨酸, 牛磺酸, 疾病模型, 动物

Abstract:

Objective  To investigate the change of metabotropic glutamate receptor 5 (mGluR5) expression level in rats with late-stage (the 7th day) traumatic brain injury (TBI) and the role of taurine.  Methods  The left cerebral TBI rat models were made by using lateral fluid percussion method. A total of 30 specific pathogen free (SPF) male Sprague-Dawley (SD) rats were randomly divided into 3 groups: sham operation group (control group), TBI model group (TBI group) and taurine treatment group (taurine group). Wet and dry weight method was used to measure the brain water content. Real-time fluorescent quantitative polymerase chain reaction (PCR) and Western blotting were used to detect the change of mRNA and protein expression of aquaporin 4 (AQP4) and mGluR5 in each group.  Results  Compared with control group, the brain water content (t = 4.893, P = 0.002), AQP4 mRNA (t = 6.523, P = 0.000) and protein (t = 4.366, P = 0.008) expression were upregulated, while mGluR5 mRNA (t = 5.776, P = 0.001) and protein (t = 3.945, P = 0.014) expression were downregulated in TBI group. After taurine treatment, the brain water content (t = 2.151, P = 0.140), AQP4 mRNA (t = 1.144，P = 0.432) and protein (t = 0.367, P = 0.804) decreased to normal, while mGluR5 mRNA (t = 1.824, P = 0.216) and protein (t = 1.185, P = 0.414) increased to normal. Correlation analysis showed brain water content was negatively correlated with mGluR5 mRNA (r = -0.617, P = 0.014) and mGluR5 protein (r = -0.665, P = 0.007), while it was positively correlated with AQP4 protein (r = 0.658, P = 0.008).  Conclusions Taurine can significantly increase the mGluR5 expression level of brain issue in the late-stage (the 7th day) of TBI and decline brain edema and brain water content. It may be a potential protective agent as an inhibitory neurotransmitter.

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