Jacquet P, Vankerkom J, Lambiet-Collier M
Department of Radioprotection, CEN/SCK, Mol, Belgium.
Int J Radiat Biol. 1994 Mar;65(3):357-67. doi: 10.1080/09553009414550421.
A comparison was made of the radiosensitivities of the resting oocyte of guinea pig in its two different states, the 'large' resting and 'contracted' oocyte, also extending the investigations to the radiosensitivity of the female germ cells at earlier stages during intrauterine life. The radiosensitivity of guinea pig oocytes was evaluated by testing the fertility of the animals 6 months and 1 year after irradiation of the ovaries with high doses (2 or 4 Gy) of X-rays. Animals had been treated in utero (target cells: oogonia and oocytes at leptotene), at birth (target cells; resting oocytes of the large type) or as adults (target cells: resting oocytes of the contracted type). No loss of fertility was evident, even 1 year after treatment, whatever the stage or dose. These investigations were completed by histological studies of the ovaries from treated and control animals. Irradiation induced a dose-dependent decrease in the total number of oocytes, and this effect was more pronounced in animals irradiated as adults (target cells: contracted resting oocytes). Our results also suggested that the LD50 of the large guinea pig resting oocyte should be around 4 Gy, a value similar to that obtained recently for the equivalent human oocyte. This confirms the high radioresistance of the guinea pig oocyte and the consequence suitability of this species for further detailed studies in relation to genetic hazards in man.
对豚鼠静止卵母细胞在两种不同状态下，即“大的”静止卵母细胞和“收缩的”卵母细胞的放射敏感性进行了比较，还将研究扩展到子宫内生命早期阶段雌性生殖细胞的放射敏感性。通过检测用高剂量（2或4 Gy）X射线照射卵巢后6个月和1年动物的生育能力，来评估豚鼠卵母细胞的放射敏感性。动物在子宫内（靶细胞：细线期的卵原细胞和卵母细胞）、出生时（靶细胞：大类型的静止卵母细胞）或成年时（靶细胞：收缩类型的静止卵母细胞）接受处理。无论处理阶段或剂量如何，即使在处理后1年，生育能力也没有明显丧失。通过对处理过的动物和对照动物的卵巢进行组织学研究，完成了这些调查。照射导致卵母细胞总数呈剂量依赖性减少，这种效应在成年时接受照射的动物（靶细胞：收缩的静止卵母细胞）中更为明显。我们的结果还表明，豚鼠大的静止卵母细胞的LD50应该在4 Gy左右，这一数值与最近在等效人类卵母细胞中获得的数值相似。这证实了豚鼠卵母细胞具有高放射抗性，以及该物种适合进一步开展与人类遗传危害相关的详细研究。
