Hendry J H
Br J Radiol. 1978 Oct;51(610):808-13. doi: 10.1259/0007-1285-51-610-808.
The reduction in the "tolerance" dose for the production of tail necrosis in adult mice seven weeks after irradiation has been measured in tails which had previously received various single or multiple tolerable doses. The major findings are: A. The ability of heavily-irradiated and healed tails to tolerate about a further 90% of the first dose was found to apply between six weeks and ten months after the first irradiation. B. The tolerance dose was reduced to about 65% of the original at the third irradiation, and this dose (approximately) remained tolerable at the fourth, fifth and sixth irradiation, all delivered at six week intervals. C. Subsequent to seven weeks after the sixth dose, late effects were observed as an atrophy of the tail, mostly distal to the healed irradiated region. The occurrence was very marked (occurring in about 40% of tails by eight months) compared with that observed after only one dose (not more than 4% by eight months). Hence, if the assay time was extended to eight months after irradiation to include these late effects, the tolerance dose for the tail after the sixth dose would be reduced to about 55% of the original value.
在先前接受过各种单次或多次可耐受剂量照射的成年小鼠尾巴中，测量了照射七周后产生尾巴坏死的“耐受”剂量的降低情况。主要发现如下：A. 发现重度照射并愈合的尾巴在首次照射后六周至十个月内，能够耐受约为首次剂量90%的额外剂量。B. 在第三次照射时，耐受剂量降至原来的约65%，并且在第四次、第五次和第六次照射时（均以六周为间隔进行），该剂量（大致）仍可耐受。C. 在第六次剂量照射七周后，观察到后期效应表现为尾巴萎缩，主要发生在愈合的照射区域远端。与仅接受一次剂量照射后（八个月时不超过4%）相比，这种情况非常明显（八个月时约40%的尾巴出现）。因此，如果将检测时间延长至照射后八个月以纳入这些后期效应，那么第六次剂量照射后尾巴的耐受剂量将降至原来值的约55%。
