Reynaud A, Travis E L
Int J Radiat Biol Relat Stud Phys Chem Med. 1984 Aug;46(2):125-34. doi: 10.1080/09553008414551201.
The response of mouse jejunum at intervals up to 1 year after single 'priming' doses of X-rays has been assessed by crypt survival after retreatment with single doses of X-rays and morphometric analysis of changes in the intestinal submucosa. The first 'priming' dose was given as a single dose to the whole abdomen. To assess crypt survival, groups of mice were retreated to the whole body with a range of test doses 2, 6 or 12 months later, while other groups of mice were given only the priming doses. These data were compared to crypt survival in mice not previously irradiated. The crypt dose-survival curves in mice re-irradiated at all three intervals after priming irradiation were displaced to higher doses in pre-treated than in non-pre-treated mice and were characterized by higher D0 values. Misonidazole given before the test exposure reversed this effect so that the dose survival curve for crypts in pre-treated mice were superimposed on that for mice not previously irradiated, suggesting that the increase in isoeffect dose and the change in the D0 in previously exposed mice was due to crypt hypoxia. Quantification of the area of the submucosa showed that its area was increased at all three times after the priming doses and was a result of collagen deposition and oedema. Thus, the hypoxia in the crypts was probably secondary to these changes. Deaths began at 6-7 months after priming irradiation and were due to intestinal obstruction and stenosis. Thus, as in other tissues, two phases of injury can be assayed in the intestine of experimental animals.
通过单次“预照射”剂量X射线后再次给予单次X射线剂量照射后的隐窝存活率以及肠道黏膜下层变化的形态计量学分析，评估了单次“预照射”剂量X射线后长达1年时间间隔内小鼠空肠的反应。首次“预照射”剂量以单次剂量照射整个腹部。为评估隐窝存活率，在2、6或12个月后用一系列测试剂量对小鼠进行全身再次照射，而其他小鼠组仅给予预照射剂量。将这些数据与未预先照射的小鼠的隐窝存活率进行比较。在预照射后的所有三个时间间隔再次照射的小鼠中，隐窝剂量存活曲线在预处理小鼠中向更高剂量偏移，且特征为更高的D0值。在测试照射前给予米索硝唑可逆转这种效应，使得预处理小鼠中隐窝的剂量存活曲线与未预先照射的小鼠的曲线重叠，这表明预先暴露小鼠中等效剂量的增加和D0的变化是由于隐窝缺氧所致。黏膜下层面积的定量分析表明，在预照射剂量后的所有三个时间点其面积均增加，这是胶原沉积和水肿的结果。因此，隐窝中的缺氧可能是这些变化的继发结果。死亡在预照射后6至7个月开始，原因是肠梗阻和肠狭窄。因此，与其他组织一样，在实验动物的肠道中可以检测到两个损伤阶段。
