用Fura-2双波长荧光法测定低剂量电离辐射对小鼠脾细胞游离钙的影响

Examination of the effect of low dose radiation on 〔Ca^(2+) 〕i in splenocytes of mice by fura-2 dual-wavelength method

目的：探讨低剂量电离辐射免疫增强效应的机理。方法：采用Ｆｕｒａ－２／ＡＭ 双波长荧光测定法研究了低剂量电离辐射全身照射后小鼠脾Ｔ淋巴细胞内游离钙离子浓度（〔Ｃａ２＋ 〕ｉ）对次佳浓度Ｃｏｎ Ａ（５ ｍ ｇ／Ｌ）反应性的变化。结果：静息状态下的小鼠脾淋巴细胞内游离钙离子浓度为９５．０±１４．０ ｎｍ ｏｌ／Ｌ，ＣｏｎＡ 可使小鼠脾Ｔ淋巴细胞内游离钙离子浓度增加６９．４±７．６ ｎｍ ｏｌ／Ｌ，上升至峰值时间为７９．２ ｓ。７５、１００ 和２００ ｍ Ｇｙ 全身照射后２４ ｈ，Ｃｏｎ Ａ 诱导的小鼠脾Ｔ淋巴细胞内游离钙离子动员明显高于假照射组（Ｐ＜ ０．０１）。结论：低剂量电离辐射的免疫兴奋效应与其增强淋巴细胞内〔Ｃａ２＋

Objective:To study the possible mechanism of immunoenhancement of low dose ionizning radiation (LDR).Methods:Fluorescent indicator fura 2 was used to measure the changes of 〔Ca 2+ 〕i response to Con A in splenocytes in Kuniming mice following LDR with X rays.Results:The resting levels of 〔Ca 2+ 〕i in splenocytes of mice were 95.0±14.4 nmol/L.The concentrations of intracellular free Ca 2+ in splenocytes after adding Con A were raised by 69.4±7.6 nmol/L,and the time of Con A stimulated 〔Ca 2+ 〕i elevation to a peak point was 72.92 sec.WBI with 75,100 and 200 mGy X rays,respectively,could enhance mitogen Con A stimulated 〔Ca 2+ 〕i elevation in splenocytes in mice 24 h after irradiation.Conclusion:The immunoenhancement effect of low dose ionizing radiation was associated with its enhancement of 〔Ca 2+ 〕i mobilization in T lymphocytes.