Tateno H, Mikamo K
Int J Radiat Biol Relat Stud Phys Chem Med. 1986 Jan;49(1):121-30. doi: 10.1080/09553008514552291.
In neonatal Chinese hamsters, all oocytes on day 0 after birth are at pachytene and ovarian X-irradiation with 1 Gy causes no acute oocyte killing. The same treatment on day 4, however, kills all diplotene-dictyate oocytes within 48 h, and consequently only a small number of pachytene oocytes survives. We investigated late effects of X-rays on the pachytene oocytes in relation to the reproductive capacity of irradiated females. There was no difference between the 0-day irradiated females and the controls with respect to the age of sexual maturation, fertility span and the rate of age-dependent reduction in the number of oocytes due to follicular atresia. On the other hand, the 4-day irradiated females showed a marked delay in sexual maturation and a very precocious cessation of oestrous cycles. However, the degeneration of the surviving oocytes was not accelerated. Fertility tests on day 18.5 of gestation revealed that there was no difference between both irradiated groups and the controls with respect to the mean number of corpora lutea and to the occurrence of dead and abnormal conceptuses. These results indicate clearly that pachytene oocytes were not affected at all by either acute or late effects of X-rays although the dose was high enough to kill diplotene-dictyate oocytes completely.
在新生中国仓鼠中，出生后第0天的所有卵母细胞都处于粗线期，用1 Gy的卵巢X射线照射不会导致急性卵母细胞死亡。然而，在第4天进行相同的处理，会在48小时内杀死所有双线期 - 核网期卵母细胞，因此只有少数粗线期卵母细胞存活。我们研究了X射线对粗线期卵母细胞的晚期影响及其与受照射雌性生殖能力的关系。在性成熟年龄、生育期以及由于卵泡闭锁导致的卵母细胞数量随年龄减少的速率方面，第0天受照射的雌性与对照组之间没有差异。另一方面，第4天受照射的雌性表现出性成熟明显延迟和发情周期非常早熟地停止。然而，存活卵母细胞的退化并没有加速。在妊娠第18.5天进行的生育力测试表明，两个受照射组与对照组在黄体平均数量以及死胎和异常胚胎的发生率方面没有差异。这些结果清楚地表明，尽管剂量高到足以完全杀死双线期 - 核网期卵母细胞，但粗线期卵母细胞根本没有受到X射线急性或晚期影响的影响。
