中文摘要：

目的：观察腺嘌呤对淋巴母细胞AHH-1辐射损伤的保护作用并探讨其作用机制。方法：照射前12h给予不同浓度的腺嘌呤，再经4．O Gy 60Coy射线照射诱发细胞凋亡，采用MTS法计算细胞存活率；Annexin V-FITC／PI双染法、Caspase3／7发光法检测细胞凋亡率；DNA Ladder法观察凋亡断裂条带；RT-PCR分析细胞Caspase-9、Bax、Bcl-2mRNA表达的变化。结果：与正常组比较，电离辐射后细胞存活率79．4％显著下降（P〈0．01，加入0．001，0．01，0．1μmol·L^-1。腺嘌呤细胞存活率分别为85．4％，89．6％，92.2％明显升高（P〈0．01），且随作用浓度的增加而增大，DNA断裂片段也减少，细胞中Caspase-9、Bax表达明显减少，Bcl-2表达明显增加，凋亡的各项指标均明显改善。结论：腺嘌呤对电离辐射诱发的细胞凋亡有保护作用，并且对细胞凋亡的抑制呈剂号依赖正相关美系．

英文摘要：

AIM： To investigate the radioprotective effect of adenine on irradiated lymphocytes and discover the possible mechanisms of protection. METHODS： Lymphocytes were pretreated for 12 h with adenine （0.001-0.1 pmol.L-1） and then exposed to 4 Gy radiation. Cell viability was observed by the MTS assay, apoptosis was detected by Annexin V-FITC/PI, DNA ladder, and caspase 3/7 activity. Caspase-9, Bax, and Bcl-2 gene expression was investigated by RT-PCR. RESULTS： Irradiation increased cell death and DNA fragmentation. Pretreatment with adenine significantly reversed this tendency. Furthermore, several anti-apoptotic characteristics of adenine were determined, including the ability to inhibit caspase 3/7, upregulate B-cell lymphoma （Bcl-2） and downregulate Bcl-2- associated X （Bax）, capase-9 gene expression in 4 Gy-irradiated AHH-1 cells. CONCLUSION： The results suggest that adenine had a radioprotective effect to inhibit apoptosis in a concentration dependent manner.