脉络丛对镉的屏阻作用及其机理探讨

Effects of choroid plexus on sequestering cadmium and its mechanism

目的 研究急性染镉后镉在中枢神经系统中的分布和GSH、巯基含量的变化。方法 分别给兔静脉注射不同剂量CdCl2 溶液 ,于 4小时和 2 4小时后处死动物 ,采集脑脊液、血液、侧脑室脉络丛、大脑皮质 ,测定其中镉含量及巯基和GSH的含量。结果 注镉后脉络丛中的镉含量明显高于脑脊液、脑皮质和血液 ;低剂量染镉组 4小时GSH的变化不明显 ,2 4小时降低 ,高剂量染镉组随时间延长GSH明显降低 ;总巯基 2 4小时低剂量染镉组显著增高 ,高剂量组明显降低。结论 侧脑室脉络丛对镉有屏阻作用 ,有助于保持脑脊液稳态 。

Objective To study the distribution of cadmium and changes in contents of glutathione(GSH)and sulfhydryl group in central nervous system of the rabbits exposed to cadmium.Methods Rabbits were given intravenously with cadmium chloride solutions of various concentrations.Cerebrospinal fluid(CSF),blood,choroid plexus and cerebral cortex were collected from the killed animals four hours and 24 hours after their exposure,respectively,and their contents of cadmium,sulfhydryl group and GSH were determined.Results Cadmium content in choroid plexus was higher than that in CSF,cerebral cortex and blood.In the low-level exposed group,GSH content did not change significantly four hours after exposure,but reduced 24 hours after exposure.In the high-level exposed group,GSH decreased significantly with length of exposure.Total sulfhydryl group content increased significantly 24 hours after exposure in the low-level exposed group and decreased significantly in the high-level exposed group.Conclusions Choroid plexus in the lateral ventricle can sequester cadmium,maintain homeostasis of CSF and protect brain from injury caused by cadmium.