UV是对生物体造成损伤的最基本的环境因子之一。检测小鼠肝细胞经UVA、UVB、UVC三种不同波段的紫外线处理后的细胞DNA损伤程度与损伤过程中的[Ca~(2+)]_i,旨在确定生物体损伤程度与UV波长和照射剂量之间的关系,对于研究UV损伤机理具有重要意义。
本文论述了生物细胞的DNA损伤的类型和成因,介绍了检测损伤的各种方法,探讨了细胞DNA损伤过程中的Ca~(2+)信号的作用机理,并进行了大量的实验论证。实验中采用的是单细胞凝胶电泳法,分别检测了小鼠肝细胞经UVA、UVB、UVC三种不同波段的紫外线处理后的细胞DNA损伤程度、不同剂量的UV对细胞造成的DNA损伤程度,用比率荧光检测法测定了在UV损伤过程中小鼠肝细胞[Ca~(2+)]_i。其结果表明:
① UV能否对细胞DNA造成损伤主要取决于UV的波长(或频率);
② UV的照射能量与其造成的细胞DNA损伤程度呈正相关;
③ 对细胞造成DNA损伤的UV具有低能量阈值和高能量平台;
④ 在UV损伤过程中[Ca~...
【英文摘要】
Through examining the DNA damage and the Ca2+ density of rat hepatocyte, which was irradiated by three kinds of different wave bands of UV, the relation between the DNA damage level and the irradiative dosage of UV was determined. [Ca2+]j during the damage was detected. Then the mechanism of UV damage and repair was revealed.Besides the types and the reasons of the DNA damage on biology cell, the various methods used to determine the damage were introduced, and the mechanism of Ca2+ signals action in the pr...