Sanderson B J, Morley A A
Mutat Res. 1986 Dec;164(6):347-51. doi: 10.1016/0165-1161(86)90027-0.
The effect of prior incubation with [3H]thymidine on survival and mutagenesis after X-irradiation of human lymphocytes was studied by incubating lymphocytes with 0.001-1.0 mu Ci/ml [3H]thymidine for 6 h at 37 degrees C and then irradiating with 150 or 300 rad. Survival was measured using lymphocyte cloning and mutagenesis was measured using 6-thioguanine selection to detect clones mutated at the hypoxanthine phosphoribosyltransferase locus. [3H]Thymidine alone had no effect on survival or mutagenesis and X-radiation alone produced the expected decrease in survival and increase in mutations. [3H]Thymidine prior to X-radiation had no effect on lethality of X-radiation but at concentrations of 0.1 and 1.0 mu Ci/ml produced a significant decrease in the number of mutations induced after both 150 and 300 rad. The results suggest that ionizing radiation, produced by disintegration of 3H, reduces the mutagenic effect of a subsequent exposure to ionizing radiation by induction of a system which prevents or repairs a restricted class of radiation damage.
通过将淋巴细胞与0.001 - 1.0微居里/毫升的[³H]胸腺嘧啶核苷在37℃下孵育6小时，然后用150或300拉德进行照射，研究了预先用[³H]胸腺嘧啶核苷孵育对人淋巴细胞X射线照射后的存活和诱变作用的影响。使用淋巴细胞克隆来测量存活率，使用6 - 硫鸟嘌呤选择来检测在次黄嘌呤磷酸核糖基转移酶位点发生突变的克隆，以此来测量诱变率。单独的[³H]胸腺嘧啶核苷对存活或诱变没有影响，单独的X射线照射导致预期的存活率下降和突变增加。X射线照射前的[³H]胸腺嘧啶核苷对X射线的致死性没有影响，但在0.1和1.0微居里/毫升的浓度下，在150和300拉德照射后诱导产生的突变数量显著减少。结果表明，由³H衰变产生的电离辐射通过诱导一种系统来减少后续暴露于电离辐射的诱变作用，该系统可预防或修复一类受限的辐射损伤。
