Geng L, Potten C S
Paterson Institute for Cancer Research, Christie Hospital, Manchester, United Kingdom.
Radiat Res. 1990 Jul;123(1):75-81.
The hair follicle or its differentiated product, the hair, which represents the linear historical record of the follicular proliferative activity, could provide a biological dosimeter of value for dose distribution determinations after accidental exposure. Here we present some further studies on irradiated mouse hair follicles and hair, and discuss the difficulties in obtaining similar data for humans. The incidence of cell death in the follicles has been shown elsewhere to be maximum 12 h after irradiation, and it increases with dose. Here we confirm that doses of 0.2-0.4 Gy can be readily detected. We show here that there is only a little more cell death in the larger follicles even though they contain many more cells and mitotic figures. About one-third of all the dead cell fragments in a follicle can be seen in a good longitudinal follicle section. Mitotic activity declines progressively with dose in the large follicles, which start with more mitotic cells, showing the dose-dependent changes most readily. The dead cells are morphologically identical to apoptotic cells at the level of the light microscope, and they fragment into several bodies, the number of which increases with dose. The total number of apoptotic bodies or fragments in whole large follicles increases almost 100-fold over a range of 1.3 Gy (from 0.2 to 1.5 Gy) and about tenfold over the range 0.2-0.5 Gy. The estimated number of dead (apoptotic) cells increases about sevenfold over the same 1.3-Gy range. The width of the middle portion of the broadest, awl, hairs measured 12 days after irradiation decreases with increasing dose. About 80% of the hairs show an obvious reduction in width after 2 Gy and the effects of a dose of about 1 Gy can be detected. The width of the hair is reduced by 10-14% per Gy. A comparison has been made between BDF1 (black) and BALB-c (albino) mice. The large follicles contain similar numbers of mitotic cells, but the BALB-c mice are more sensitive both in terms of the radiation-induced apoptosis and in terms of a reduction in awl hair width.
毛囊或其分化产物毛发代表了毛囊增殖活性的线性历史记录，可为意外暴露后剂量分布的测定提供有价值的生物剂量计。在此，我们展示了一些关于受辐照小鼠毛囊和毛发的进一步研究，并讨论了获取人类类似数据的困难。毛囊中细胞死亡的发生率在其他地方已表明在辐照后12小时最高，且随剂量增加而上升。在此我们证实0.2 - 0.4 Gy的剂量很容易被检测到。我们在此表明，即使较大的毛囊含有更多的细胞和有丝分裂图像，其中的细胞死亡也仅略多一点。在一个良好的毛囊纵切面上，可以看到毛囊中约三分之一的死亡细胞碎片。大毛囊中的有丝分裂活性随剂量逐渐下降，大毛囊起始时有更多的有丝分裂细胞，最容易显示出剂量依赖性变化。在光学显微镜水平上，死亡细胞在形态上与凋亡细胞相同，它们会分裂成几个小体，其数量随剂量增加。在1.3 Gy（从0.2到1.5 Gy）范围内，整个大毛囊中凋亡小体或碎片的总数增加近100倍，在0.2 - 0.5 Gy范围内增加约10倍。在相同的1.3 Gy范围内，估计的死亡（凋亡）细胞数量增加约7倍。辐照后12天测量的最宽的锥形毛发中间部分的宽度随剂量增加而减小。2 Gy后约80%的毛发宽度有明显减小，约1 Gy剂量的影响可以被检测到。毛发宽度每Gy减少10 - 14%。已对BDF1（黑色）和BALB - c（白化）小鼠进行了比较。大毛囊中含有相似数量的有丝分裂细胞，但就辐射诱导的凋亡和锥形毛发宽度减小而言，BALB - c小鼠更敏感。
