8-氧鸟嘌呤脱氧核苷在快速老化小鼠SAMP8海马中表达的增龄性变化研究

The Age-related Increase of 8-oxo-7,8-dihydroguanine in the Hippocampus of Senescence-accelerated Mice Prone 8

目的观察8-氧鸟嘌呤脱氧核苷(8-oxo-7,8-dihydroguanine,8-oxo-dG)在快速老化小鼠SAMP8海马不同区域的表达,探讨其变化与SAMP8增龄的关系。方法选用1、4、8、12月龄快速老化小鼠SAMP8(每组各6只),对照组为同龄抗快速老化小鼠SAMR1(每组各6只),用免疫组化法检测海马不同区域内8-oxo-dG的表达水平。结果8-oxo-dG在海马不同区域均有表达,且主要在海马神经细胞胞核内表达。对照组SAMR1小鼠海马各区域8-oxo-dG的吸光度定量结果显示各月龄组间无统计学差异(P>0.05);1、4月龄组SAMP8小鼠海马各区域8-oxo-dG的吸光度定量结果与同龄匹配的SAMR1小鼠间无统计学差异(P>0.05);8、12月龄组SAMP8小鼠海马各区域8-oxo-dG的吸光度定量结果分别显著高于1月龄和4月龄组(P<0.05),也分别显著高于同龄SAMP1对照组(P<0.05)。结论8-oxo-dG在SAMP8快速老化小鼠海马中的水平随增龄而显著增高。

Objective To investigate the age-related expression of 8-oxo-7,8-dihydroguanine （8-oxo-dG） in the mouse hippocampus of senescence-accelerated mice prone 8（SAMP8）. Methods Randomly selected 1-, 4-, 8- and 12-month old SAMP8 and the age-matched control strain accelerated mice resistant 1 （SAMR1）, with 6 mice in each group, immunohistochemistry analysis was used to explore the ways of change in the two strains of mice. Results 8-oxo-dG could be detected almost exclusively in the nuclei of neurons throughout the whole hippocampus of both strains at all tested age groups. No significant change was observed in CA1 and CA3 subregions among the four SAMR1 groups. Compared with the age-matched SAMR1 mice, no significant difference in 8-oxo-dG expression was observed in 1- and 4-month SAMP8 mice. However, significant increases of 8-oxo-dG in 8- and 12-month SAMP8 mice were observed, compared with the 1-month SMP8 group and with the age-matched SAMR1 groups. The pattern of change in CA3 was similar with that in CA1. ConeluSiolm 8-oxo-dG in the hippocampus of SAMP8 mice increased markedly with the gaining of age.