信号因子对辐射诱导胸腺淋巴细胞凋亡的影响

Effect of signal factors on lymphocyte apoptosis in mouse thymus induced by ionizing radiation in vitro

目的 观察信号因子皮质酮 (CS)、cAMP、cGMP、Ca2 + 和蛋白激酶C(PKC)对体外 4GyX射线照射诱导小鼠胸腺淋巴细胞凋亡的影响。方法 应用荧光发光分光光度仪检测胸腺淋巴细胞DNA裂解率。结果 2～ 8Gy照射后 4～ 8h ,胸腺淋巴细胞DNA裂解率均明显高于对照组 (P <0 0 1)。与对照组比较 ,加入 0 0 1μmol LCS、5 0ng mlcAMP、0 0 5～ 0 4 μg mlCa2 + 结合载体离子霉素(Iono)和 0 0 5～ 0 4ng mlPKC激活剂豆蔻酰佛波醇乙酯 (PMA)均明显增加淋巴细胞DNA裂解率 ,P <0 0 5或 <0 0 1,而加入 5 0ng mlcGMP与对照组比较 ,无明显作用。对 0 0 1μmol LCS、5 0ng mlcAMP、0 2和 0 4 μg mlIono及 0 2和 0 4ng mlPMA分别加 4Gy照射 ,其DNA裂解率均明显高于单纯 4Gy照射组 ,P <0 0 5或 <0 0 1,而 5 0ng mlcGMP加 4Gy照射与单纯 4Gy照射组比较无明显差异。结论 在一定剂量范围内 ,信号因子CS、cAMP、Ca2 +

Objective\ To observe the effects of corticosterone (CS),cAMP,cGMP,Ca^(2+) and protein kinas C(PKC) signal factors on lymphocyte apoptosis in mouse thymus induced by ionizing radiation of 4 Gy X-rays in vitro. Method\ The DNA lytic rate of lymphocytes in thymus was measured with fluorospectrophotometry. Results\ The DNA lytic rates of lymphocytes in thymus 4-8 h after irradiation with 2-8 Gy were all significantly higher than those of the control.As compared with the control,the DNA lytic rates of lymphocytes all increased significantly in 0.01 μmol/L CS(P<0.01),50 ng/ml cAMP (P<0.01),0.05-0.4 μg/ml ionomycin (Iono,(P<0.05) or P<0.01) and 0.05-0.4 ng/ml phorbol myristate acetate (PMA,P<0.05 or P<0.01) groups,respectively,while the rate in 50 ng/ml cGMP did not increase significantly.The DNA lytic rates of lymphocytes were significantly higher in 0.01 μmol/L CS(P<0.01),50 ng/ml cAMP (P<0.01),0.2 and 0.4 μg/ml Iono (P<0.05) and 0.2 and 0.4 ng/ml PMA (P<0.05) plus 4 Gy-irradiation groups respectively than that in single 4 Gy-irradiation group,while that in 50 ng/ml cGMP plus 4 Gy-irradiation group was not.As both Iono and PMA were combined to act to the lymphocytes,the DNA lytic rate of only in 0.4 μg/ml Iono and 0.4 ng/ml PMA group was significantly higher than that in the control (P<0.01);the rate in 0.4 μg/ml Iono and 0.4 ng/ml PMA plus 4 Gy-irradiation group was significantly higher than that in the single 4 Gy-irradiation group (P<0.05),but was not significantly higher than that in the 0.4 μg/ml Iono plus 4 Gy-irradiation group or 0.4 ng/ml PMA plus 4 Gy-irradiation group. Conclusion\ There are promoting effects of CS,cAMP,Ca^(2+) and PKC signal factors in certain dose ranges on lymphocyte apoptosis in mouse thymus induced by ionizing radiation with larger dose of X-rays.\;