巴西苏木红素对小鼠脑缺血中能量代谢的影响

目的:研究巴西苏木红素对小鼠脑缺血损伤中能量代谢的影响作用。方法:将40只小鼠随机分为假手术组、脑缺血组、苏木红素5,10 mg.kg-1组,每组10只,构建脑缺血模型。脑缺血手术前3 d开始静脉注射苏木红素,给药剂量依据预试验确定,随后处死小鼠,制备大脑匀浆液。利用HPLC对脑内三磷酸腺苷、二磷酸腺苷、腺苷一磷酸和乳酸含量进行测定,RT-PCR检测脑内单羧酸转运体(MCT1,MCT2)基因水平的表达。结果:小鼠脑缺血20 min后,脑内乳酸含量迅速升高,再灌注1 h内逐渐减低,再灌注24 h后逐渐降低至正常水平。缺血再灌的最初,能荷值迅速显著减低,再灌1 h过程中能荷恢复较快,但再灌24 h后能荷仍未恢复至正常水平。脑缺血过程中,随着脑内乳酸的升高,MCT1和MCT2的表达也随之上调,预先静脉注射苏木红素5 mg.kg-1能上调MCT2 mRNA的表达,与模型组相比差异显著(P0.05),苏木红素10 mg.kg-1组能上调MCT1和MCT2 mRNA的表达,与模型组相比差异显著(P0.01)。结论:苏木红素所具有的神经保护作用可能是通过改善能荷水平而实现的。

Effect of brazilein on energy metabolism of cerebral ischemia-reperfusion in mice

Objective : To investigate brazilein's role in energy metabolism of cerebral ischemia-reperfusion in mice. Method : Fourty mice were randomly divided into the sham group, ischemia group, brazilein 5 mg·kg^-1 group and brazilein 10 mg·kg^-1 group, each with ten cases. Cerebral ischemia model was the built. Mice were injected with brazilein three days before the operation, then they were killed. Cerebrum homogenate was prepared for the detecting of ATP, ADP, AMP and lactic acid by HPLC, expressions of MCT1 and MCT2 in mRNA level by RT-PCR. Result : The lactic acid in cerebrum increased sharply 20 minutes after cerebral ischemia and decreased 1 hour after reperfusion, then returned to the normal level 24 hours after reperfusion. The charge of energy decreased significantly at the beginning of the ischemia-reperfusion, and the charge restored 1 hour after reperfusion though it was still much lower than the normal level at the time point of 24 hours. Moreover, MCT1 and MCT2 upregulated accompanied with the increase of lactate, MCT2 mRNA enhanced in brazilein 5 mg·kg^-1 group (P<0.05) while both the two factors increased in brazilein 10 mg·kg^-1 group (P<0.01). Conclusion : Brazilein might protect neurons by changing the charge of energy.