牛磺酸对重度颅脑创伤大鼠脑组织AQP4/牛磺酸转运体基因的影响

目的研究牛磺酸（Tau）对重度颅脑创伤（TBI）大鼠脑组织的脑组织含水量、水通道蛋白-4（AQP-4）/Tau转运体（TAUT）基因表达的影响。方法按随机数字表法将84只雄性SD大鼠分为7组：假手术组（Sham组）、脑外伤组（TBI组）、Tau治疗组（Tau组）,Tau预防组（Pre-Tau组）、β-丙氨酸组（β-Ala组）、维生素C组（Vc组）、叶酸组（Fa组）,每组12只。后6组均采用液压打击制作重度TBI模型。造模成功后即刻尾静脉给药200 mg/kg。Sham组和TBI组给予相同量等渗盐水,24 h后取脑。采用HE染色法观察TBI后各组脑组织形态学变化、测定脑组织含水量,用荧光定量RT-PCR方法检测AQP-4/TAUT基因表达。结果形态学检查：TBI 24 h后,神经细胞肿胀,细胞丢失,细胞核固缩,突起短小消失,坏死灶边缘可见炎性细胞浸润,β-Ala组同TBI组。但与TBI组比较,Tau组、Vc组、Fa组、Pre-Tau组形态上无显著改善;脑组织含水量：与Sham组相比,TBI组、β-Ala组伤后24 h显著升高（P〈0.05）。而Tau组、Vc组、Fa组明显降低,与Sham组无统计学差异;Pre-Tau组显著低于Sham组（P〈0.05）。基因表达：与Sham组相比,TBI组脑组织AQP-4 mRNA表达量显著升高（P〈0.05）,Fa组TAUT mRNA表达量显著升高（P〈0.05）。结论 Tau、Vc、Fa及Tau预防性治疗均可以显著降低脑水肿和AQP-4基因表达,对TBI后脑水肿有较好的治疗作用,但Tau、Vc对TBI早期的TAUT无调节作用,其对脑组织含水量的有效性并不是通过调节TAUT实现的。

Effect of Taurine on AQP4/Taurine transporter gene in rats with traumatic brain injury

Objective To investigate the changes of the brain water content and AQP4/taurine transporter gene expression in brain tissue after taurine treatment in rats with traumatic brain injury（TBI）.Methods A total of 84 male SD rats were randomly divided into 7 groups： Sham group,traumatic brain injury TBI group,Tau group,Pre-Tau group,β-Ala group,Vc group,Fa group.TBI models of the latter six groups were performed by lateral fluid percussion.The rats were administered drugs（drug dose 200 mg/kg） intravenously immediately after TBI.Sham group and TBI group were given isotonic saline.The histopatho1ogical changes of brain tissue were observed by HE stain.Brain water content was measured by the dry-wet weight assay,the expression of AQP4/TAUT gene was analyzed by fluorescence quantitative RT-PCR after TBI 24 hours.Results Morphology： TBI rats presented typical brain edema which the neuron swelling,cell losing,karyopyknosis and inflammatory cells infiltrated at the edge of necrosis at 24 h after TBI.However,compared with TBI group,morphology of the cells of Tau group,Vc group,Fa group and Pre-Tau group had not obviously changed;the change of β-Ala group was the same as TBI group.Brain water content： the brain water content of TBI group and β-Ala group significantly increased campaired with Sham group.The brain water content of Pre-Tau group was significantly lower than that of Sham group.Gene expression： the expression of AQP-4 mRNA of TBI group was significantly higher than that of Sham group;the expression of TAUT mRNA of Fa group was significantly higher than that of Sham group.Conclusions Tau,Vc,Fa and taurine preventive treatment could significantly reduce brain edema and down-regulate the expression of AQP-4 gene and have the therapeutic effect on brain edema after traumatic brain injury.Tau and Vc have no effects on TAUT regulation after TBI,and their effects on the brain water content are not by adjusting the TAUT to achieve.