叶酸对脑梗塞大鼠神经细胞凋亡及Notch1 mRNA表达的影响

目的研究叶酸(FA)对脑梗塞大鼠缺血侧脑组织内神经细胞凋亡及Notch1 mRNA表达的影响。方法雄性SD大鼠48只按体重随机分为4组:假手术组(SO)、大脑中动脉梗塞组(MCAO)、MCAO+叶酸低剂量组(MCAO+LFA)、MCAO+叶酸高剂量组(MCAO+HFA)。除SO组外,其他三组均采用线拴法制作大鼠大脑中动脉栓塞,各组于栓塞处理后第14天处死。补充叶酸前、补充28天后及栓塞处理后第14天,采用化学发光免疫法测定各组大鼠血清叶酸含量;建立MCAO后第14天,应用TUNEL法测定缺血侧脑组织内神经细胞的凋亡,荧光原位杂交法检测神经细胞内Notch1 mRNA的表达。结果补充叶酸后,与MCAO组相比,MCAO+LFA、MCAO+HFA组神经细胞凋亡率明显降低(P<0.01),血清叶酸浓度及Notch1 mRNA的荧光强度值均明显升高(P<0.01)。结论叶酸降低脑梗塞大鼠神经细胞凋亡率可能与其促进Notch1 mRNA的表达有关。

Effects of folic acid on neural cell apoptosis and Notch1 mRNA expression in rats with brain infarction

Objective To investigate the effects of folic acid(FA) on neural cell apoptosis and Notch1 mRNA expression in the ischemic brain tissues of rats with brain infarction.Methods Forty-eight male SD(Sprague-Dawley)rats were randomly separated into 4 groups according to body mass: Sham operation(SO),middle cerebral artery occlusion(MCAO),MCAO + low dose folic acid(MCAO + LFA),and MCAO + high dose folic acid(MCAO + HFA).MCAO was made by operation with middle cerebral artery occlusion method except for SO,and the rats were executed at the 14thd after MCAO.Serum folic acid contents were measured with immune chemiluminescence before and 28d after folic acid supplementation and 14d after MCAO.Ischemic brain tissues neural cell apoptosis was measured with TUNEL method,Notch1 mRNA expression was detected by fluorescence in situ hybridization at the 14thd after the rats with MCAO.Results In comparison with MCAO,the rates of neural cell apoptosis were more lower,the concentrations of serum folic acid and the fluorescence intensity of Notch1 mRNA were more higher than those in both MCAO+LFA and MCAO+HFA after FA supplementation(P<0.01).Conclusion The rates of neural cell apoptosis induced by FA associated with the increase of Notch1 mRNA expression.