Julia A M, Bachaud J M, Canal P, Daly N J
Centre Claudius Regaud, Toulouse, France.
Int J Radiat Oncol Biol Phys. 1991 Feb;20(2):343-5. doi: 10.1016/0360-3016(91)90117-m.
Pretreatment of mice with a single radiation dose of 11.5 Gy or with fractionated irradiation (2 x 6.5 or 7.5 Gy, with an interval time of 12 hr) led to a relative decrease in the radiosensitivity of jejunal crypt cells when a second single dose of radiation was delivered 2 months later. When the same irradiation pretreatment was combined with CDDP (6 mg/kg, i.p.) injected 12 hr after single radiation or between two equal doses of radiation, similar crypt cells resistance was obtained. The combination of CDDP with irradiation did not modify the radiosensitivity of jejunal crypts in comparison with irradiation alone, even when the total radiation dose was delivered in 2 split doses. This induced radioresistance was demonstrated to be a reflection of late injury on intestinal tissue, presumably due to hypoxia resulting from vascular damage. It seems that the administration of CDDP did not change the possible hypoxia suspected in crypt cells of mice pretreated with single radiation dose. However, mouse lethality increased significantly when CDDP was combined with irradiation.
用11.5 Gy的单次辐射剂量或分次照射（2×6.5或7.5 Gy，间隔时间为12小时）对小鼠进行预处理，在2个月后给予第二次单次辐射剂量时，空肠隐窝细胞的放射敏感性相对降低。当相同的辐射预处理与单次辐射后12小时或两次等量辐射之间腹腔注射顺铂（6 mg/kg）相结合时，可获得类似的隐窝细胞抗性。与单独照射相比，顺铂与照射联合使用并未改变空肠隐窝的放射敏感性，即使总辐射剂量分两次给予。这种诱导的放射抗性被证明是肠道组织晚期损伤的反映，可能是由于血管损伤导致的缺氧。似乎顺铂的给药并没有改变单次辐射剂量预处理的小鼠隐窝细胞中可能存在的缺氧情况。然而，当顺铂与照射联合使用时，小鼠的致死率显著增加。
