Müller Wolfgang Ulrich, Rode Achim
Institut für Medizinische Strahlenbiologie, Universitätsklinikum Essen, Essen, Germany.
Mutat Res. 2002 May 22;502(1-2):47-51. doi: 10.1016/s0027-5107(02)00022-2.
Individuals can be exposed to high doses (more than 5Gy) during radiation accidents. It is, of course, helpful to the physician to have biological indicators also for such high doses. The problem with most cytogenetic indicators is, that the response levels off at doses starting around 5-7Gy of low LET radiation and that the dose-response curve even declines after doses exceeding about 10Gy. Thus, it may be difficult to decide, whether the dose was, for example, 8 or 14Gy. We studied how the micronucleus assay can be used to give information also in the high dose range. It turned out that micronucleus frequency itself cannot be used for the estimation of doses exceeding about 5-7Gy. There are, however, at least three other endpoints that can be determined in the cytochalasin B assay that can assist the decision in the high dose range: (1) the number of mononucleated cells; (2) the ratio of tri- to tetranucleated cells; (3) the average micronucleus frequency in micronucleus positive binucleated cells.
在辐射事故中，个人可能会受到高剂量（超过5Gy）的辐射。当然，对于医生来说，拥有针对此类高剂量的生物指标是有帮助的。大多数细胞遗传学指标的问题在于，对于低LET辐射，在剂量约为5 - 7Gy左右时反应趋于平稳，并且在超过约10Gy的剂量后剂量反应曲线甚至会下降。因此，可能很难确定剂量例如是8Gy还是14Gy。我们研究了微核试验如何也能在高剂量范围内提供信息。结果表明，微核频率本身不能用于估计超过约5 - 7Gy的剂量。然而，在细胞松弛素B试验中至少还有其他三个终点可以确定，它们可以在高剂量范围内辅助决策：（1）单核细胞的数量；（2）三核细胞与四核细胞的比例；（3）微核阳性双核细胞中的平均微核频率。
