Zn对细胞保护作用机理的研究

应用扫描质子微探针和同步辐射ｘ荧光分析技术测定了细胞中元素的分布和组成，为确定Zn是细胞结构成分提供了直接的实验依据.用上述核技术结合有关生化指标，分析测定了正常和损伤细胞（脂质过氧化损伤）中Fe，Zn和丙二醛、SH基含量变化的相互关系.实验结果表明，当细胞发生脂质过氧化损伤时，Fe含量和丙二醛含量同步增高，而Zn含量和SH基量则降低.给细胞补充Zn后，提高了细胞质膜中的Zn含量，SH基量也随之增加，同时丙二醛量降低.提示Zn保护细胞完整性的作用机理之一是控制脂质过氧化作用.Zn可保护膜蛋白的SH基，减少和阻止被Fe所催化的过氧化反应.

Study on the Mechanism of Protective Effet of Zinc to Cells

On analyzing the distribution and composition of element in single cell with scanning proton microprobe (SPM) and synchrotron radiation X-Ray fluoroscence microprobe (SR-XMF) it shows that zinc is a constituent of cell plasma. The levels of cellular zinc and iron were detectecd by above nuclear technique and the contents of MDA, SH group were estimated respectively by biochemical method for both normal and injured cell induced an peroxidation damage by hydroxyl-free radical. It was found that MDA content increased, SH group decreased. as well as Fe / Zn ratio raised during lipoperoxidation. By supplementation of zinc to culture medium. the inhibitory effect of zinc on lipoperoxidation was obvious from following experiment results that MDA content decreased. SH group content increased as well as Fe / Zn ratio reduced. The results suggest that zinc plays a role in maintaining the integrity of the cell and protects SH group of membrane protein thus preventing catalytic peroxidation reaction of iron.