Response to fission neutron irradiation of spermatogonial stem cells in different stages of the cycle of the seminiferous epithelium.
Response to fission neutron irradiation of spermatogonial stem cells in different stages of the cycle of the seminiferous epithelium.
复制标题
生精上皮周期不同阶段精原干细胞对裂变中子照射的反应。
作者：
M. van Beek;J. Davids;H. V. D. van de Kant;D. D. de Rooij
用1Gy裂变中子照射小鼠。照射后每隔15天，在整个生精小管上皮周期的8个阶段，对未分化的精原细胞进行计数。从第6天开始，照射期间处于IV-VII阶段的区域的精原细胞数量低于处于IX-II阶段的区域。前者的最小数量比后者低2至6倍。处于第三阶段或第八阶段的地区给出了中间值。结果表明，上皮细胞周期可分为两部分，对辐射的反应不同，分别在第III和第VIII阶段开始或结束，第III-VIII部分和第VIII-III部分分别占上皮周期的45%和55%。在第15天，部分-III的控制水平再次被发现，而第三部分-的精原细胞数量仍然很低。在对照组中，发现第VIII-III部分对应于干细胞的高增殖活性时期，而在第III-VIII部分，增殖活性非常低。这可能会影响它们的辐射敏感性和/或辐射后的增殖行为，导致上皮周期的两个部分出现不同的精原细胞数量。与正常上皮不同，照射后可见奇数克隆(不含2“细胞)，以及组成细胞聚集在一起的Apr和Aal克隆。
Mice were irradiated with 1 Gy of fission neutrons. At intervals up to 15 days after irradiation undifferentiated spermatogonia were counted in whole mounts of seminiferous tubules in up to eight stages of the epithelial cycle. From Day 6 onward lower numbers of spermatogonia were found in the areas which were in stages IV-VII during irradiation than in those which were in stages IX-II. Minimal numbers in the former area were two to six times lower than those in the latter one. Areas which were in stages III or VIII gave intermediate values. It is concluded that the epithelial cycle can be divided into two parts with a different response to irradiation, that begin or end in stages III and VIII. Part III-VIII and part VIII-III comprise 45 and 55% of the epithelial cycle, respectively. In part VIII-III control levels were found again at Day 15, while in part III-VIII spermatogonial numbers were still very low. In controls it was found that part VIII-III corresponds to a period of high proliferative activity of the stem cells, while in part III-VIII the proliferative activity is very low. This may affect their radiosensitivity and/or their proliferative behavior after irradiation, resulting in different spermatogonial numbers in the two parts of the epithelial cycle. Unlike in normal epithelium, after irradiation giant cells, odd-numbered clones (not containing 2" cells), and clones of Apr and Aal , in which the composing cells clump together, were observed.