Osman P
J Reprod Fertil. 1985 Jan;73(1):261-70. doi: 10.1530/jrf.0.0730261.
Ovarian follicles (greater than or equal to 100 X 10(5) microns 3 or a mean diameter of greater than or equal to 275 microns) in adult rats were classified as non-atretic and atretic during the oestrous cycle and recorded in 5 volume classes. The atretic follicles were also categorized in several stages according to the progress of atresia. The degeneration of the entire granulosa wall until the induced changes in the oocyte took at least 24 h. Another 24 h elapsed before the oocyte became denuded. Therefore the % of atretic follicles, i.e. follicles in all stages of atresia, could not be used as indicator for the rate of atresia. The atretic portion in the follicle population greater than or equal to 100 X 10(5) microns 3 increased from early dioestrus 1 to early dioestrus 3, reached a plateau during dioestrus 3 and pro-oestrus, and declined at late oestrus to the level of early dioestrus 1. The sudden decrease in number of atretic follicles after late pro-oestrus was caused by the discard of many atretic follicles in the advanced stages due to various deformities as revealed by histological observation. By using the % of atretic follicles in the earliest stage as indicator of atretic rate, two waves of atresia were found affecting the population of antral follicles during their growth, the first at dioestrus 1 amounting to 15-20% and then at dioestrus 3, affecting 35% of the population. The present study also shows the extension of atresia in the various volume classes of follicles during the oestrous cycle. A pool of approximately 7 follicles in the smallest volume class was maintained after ovulation, grew further in the next cycle with a new cohort of 20 follicles, and seemed to provide the required number of follicles destined to ovulate. This suggests that the follicles that ovulate were already present at an antral stage in the preceding cycle and needed two cycles for their growth to ovulation.
成年大鼠卵巢卵泡（体积大于或等于100×10⁵立方微米或平均直径大于或等于275微米）在发情周期中被分为非闭锁卵泡和闭锁卵泡，并记录在5个体积类别中。闭锁卵泡也根据闭锁进展分为几个阶段。整个颗粒层壁的退化直至卵母细胞发生诱导变化至少需要24小时。卵母细胞裸露还需要另外24小时。因此，闭锁卵泡的百分比，即处于所有闭锁阶段的卵泡，不能用作闭锁率的指标。在体积大于或等于100×10⁵立方微米的卵泡群体中，闭锁部分从间情期1早期到间情期3早期增加，在间情期3和发情前期达到平台期，并在发情后期下降到间情期1早期的水平。发情后期后闭锁卵泡数量的突然减少是由于组织学观察发现许多处于晚期的闭锁卵泡因各种畸形而被淘汰。以最早阶段闭锁卵泡的百分比作为闭锁率指标，发现有两波闭锁影响窦状卵泡群体在其生长过程中，第一波在间情期1，占15 - 20%，然后在间情期3，影响35%的群体。本研究还显示了发情周期中不同体积类别的卵泡闭锁的扩展情况。排卵后最小体积类别的卵泡池中约有7个卵泡得以保留，在下一个周期中随着20个新卵泡群体的加入而进一步生长，似乎提供了注定要排卵的所需卵泡数量。这表明排卵的卵泡在前一个周期的窦状阶段就已存在，需要两个周期才能生长到排卵阶段。
