The polycystic ovarian (PCO) condition: apoptosis and epithelialization of the ovarian antral follicles are aspects of cystogenesis in the dehydroepiandrosterone (DHEA)-treated rat model.

This investigation was designed to study apoptosis and epithelialization during cystogenesis of the dehydroepiandrosterone rat model. Using in situ DNA 3'- end-labeling with non-radioactive digoxigenindidesoxy-UTP (dig-ddUTP), apoptosis is initially seen in cumulus granulosa cells and other granulosa cells facing the antrum. During cystogenesis, apoptosis systematically progresses from the cumulus towards the mural granulosa layer. In contrast, granulosa cells of atretic follicles undergo apoptosis in a random manner. The outer layer of mural granulosa cells during cystogenesis escapes apoptosis. Granulosa cells contain vimentin. However, the outer mural granulosa cell layer that lines the cyst acquires keratin. In addition to being associated with each other via gap junctions, the outer layer of granulosa cells acquire tight junctions. With the characterization of the transformation of the outer mural granulosa cells into a characteristic epithelium and the orderly progression of apoptosis, we further the understanding of the multifaceted process of cystogenesis of the ovarian antral follicle.