Belli M, Cera F, Cherubini R, Ianzini F, Moschini G, Sapora O, Simone G, Tabocchini M A, Tiveron P
Laboratorio di Fisica, Istituto Superiore di Sanità, Rome, Italy.
Int J Radiat Biol. 1991 Feb;59(2):459-65. doi: 10.1080/09553009114550411.
The mutation induction at the HGPRT locus has been studied in V79-753B Chinese hamster cells irradiated with proton beams with energies of 3.36, 1.70 and 1.16 MeV, corresponding to average LET values of 10.6, 17.8 and 23.9 keV/microns, respectively. The mutation curve obtained with 200 kV X-rays was used for comparison. The mutation frequency induced by all the proton beams is considerably higher than that induced at the same dose by X-rays and it is linearly related to the dose. Moreover, the proton effectiveness increases with the LET. The RBEs (evaluated as the initial slope ratios) are 5.0 +/- 0.8, 5.4 +/- 0.8 and 7.7 +/- 1.2 for protons with average LETs of 10.6, 17.8 and 23.9 keV/microns, respectively. These values are higher than those reported in the literature for other ions of comparable LET. This finding parallels what we have already found for cell inactivation (for which RBEs of 3.0, 4.6 and 7.3 were obtained at the same LETs), and indicates that for mutation induction, also, the RBE-LET relationship may depend on the type of radiation.
已在用能量分别为3.36、1.70和1.16 MeV的质子束照射的V79 - 753B中国仓鼠细胞中研究了次黄嘌呤 - 鸟嘌呤磷酸核糖转移酶（HGPRT）位点的突变诱导情况，这些能量分别对应平均传能线密度（LET）值为10.6、17.8和23.9 keV/微米。使用200 kV X射线获得的突变曲线用于比较。所有质子束诱导的突变频率都显著高于相同剂量X射线诱导的突变频率，并且与剂量呈线性关系。此外，质子的有效性随LET增加。对于平均LET分别为10.6、17.8和23.9 keV/微米的质子，相对生物效应（RBE，以初始斜率比评估）分别为5.0±0.8、5.4±0.8和7.7±1.2。这些值高于文献中报道的其他具有可比LET的离子的值。这一发现与我们已经在细胞失活方面发现的情况相似（在相同LET下获得的RBE分别为3.0、4.6和7.3），并表明对于突变诱导，RBE - LET关系也可能取决于辐射类型。
