Morris G M, Hopewell J W
Research Institute, University of Oxford, Churchill Hospital.
Br J Radiol. 1988 Mar;61(723):205-11. doi: 10.1259/0007-1285-61-723-205.
Changes in the cell kinetics of pig epidermis have been investigated after irradiation with single doses of 15 Gy and 20 Gy of X rays. The epidermis exhibited an initial degenerative phase when the rate of cell depletion was independent of radiation dose. Changes consistent with repopulation were evident between the 14th and 18th day after irradiation. The severity of cell depletion and the rate of recovery of the epidermis were dose dependent. The regenerative phase was characterized by an increased cell proliferation; values for the labelling index (LI) were greater than those in the non-irradiated epidermis, from 14 days after 15 Gy and from 18 days after 20 Gy. The LI was still elevated at the end of the observation period, i.e. Day 56. No change in the time for DNA synthesis was found. Eighteen days after 15 Gy and 22 days after 20 Gy, islands of cells (colonies), with an appearance similar to the cells in the normal epidermis, were seen. The minimum turnover time (TT) for the proliferating cells of the basal layer of the epidermis in radiation-damaged skin was 61-68 h as compared with 125 h in unirradiated skin. For the basal cells in the colonies, TT was 16-22 h.
用15戈瑞和20戈瑞的单次X射线剂量照射猪表皮后，对其细胞动力学变化进行了研究。表皮在照射后呈现出一个初始的退化阶段，此时细胞耗竭率与辐射剂量无关。在照射后第14天至第18天之间，明显出现了与细胞再增殖一致的变化。细胞耗竭的严重程度和表皮的恢复速度与剂量相关。再生阶段的特征是细胞增殖增加；标记指数（LI）的值在15戈瑞照射后14天以及20戈瑞照射后18天开始大于未照射表皮中的值。在观察期结束时，即第56天，LI仍然升高。未发现DNA合成时间有变化。在15戈瑞照射后18天以及20戈瑞照射后22天，可见到细胞岛（集落），其外观与正常表皮中的细胞相似。与未照射皮肤中125小时相比，辐射损伤皮肤中表皮基底层增殖细胞的最短周转时间（TT）为61 - 68小时。对于集落中的基底细胞，TT为16 - 22小时。
