The goal of this study was to determine whether the quantification of the nucleolar organizer regions (AgNORs) is a useful parameter for evaluation of the proliferative potential of non-neoplastic granulosa cells in ovarian follicles at different stages of development. Seven ovaries from six-month-old rats, all of which in metestrus-diestrus, were studied. The number of AgNORs from 60 granulosa cell nuclei was quantified in secondary follicles with two to three layers of cells and in follicles with more than five layers of granulosa cells. Follicles with two to three layers had larger AgNORs in lower numbers, whereas more developed secondary follicles the AgNORs were predominantly smaller, scattered throughout the nucleus, and in significantly higher numbers. In conclusion, quantification of the nucleolar organizer regions is an appropriate parameter for differentiation of the proliferative potential of non-neoplastic granulosa cells.
rat; ovary; granulosa cells; AgNORs
