本文采用TUNEL法及流式细胞仪观察不同鼠龄外周血淋巴细胞凋亡及凋亡发生率 ,并用免疫组织化学检测Bcl 2、Bcl xl及Bax基因表达变化。结果发现老年鼠组外周血淋巴细胞群中存有典型的凋亡细胞 ,凋亡细胞发生率明显高于青年组。老年鼠PBL的Bcl 2 ,Bcl xl表达下调 ,而Bax的表达量明显增加。提示在衰老过程中存在着免疫细胞凋亡 ,其发生与相关调控基因的表达一致。 In this paper, TUNEL method and flow cytometry were used to observe the apoptosis of peripheral blood lymphocytes and the incidence of apoptosis in different age groups. The expressions of Bcl-2, Bcl-xl and Bax were detected by immunohistochemistry. The results showed that there were typical apoptotic cells in the peripheral blood lymphocyte population of aged mice, the incidence of apoptotic cells was significantly higher than that of the young group. The expression of Bcl 2 and Bcl xl was down-regulated in PBL of old mice, while the expression of Bax was significantly increased. Tip in the aging process there is immune cell apoptosis, its occurrence and regulation of gene expression consistent.