BOR - Papers in Press, published online ahead of print
June 2, 2004.
Biol Reprod 2004, 10.1095/biolreprod.104.029652
BIOLOGY OF REPRODUCTION 71, 10711078 (2004)
DOI: 10.1095/biolreprod.104.029652
© 2004 by the Society for the Study of Reproduction, Inc.
Theca Interna: The Other Side of Bovine Follicular Atresia1
Leigh J. Clark3,
Helen F. Irving-Rodgers3,
Arun M. Dharmarajan4, and
Raymond J. Rodgers2,3
Centre for Reproductive Health,3 Department of Obstetrics and Gynaecology, The University of Adelaide, Adelaide, South Australia 5005, Australia
School of Anatomy and Human Biology,4 The University of Western Australia, Crawley, Western Australia 6009, Australia
Currently, histological classifications of ovarian follicular atresia are almost exclusively based on the morphology of the membrana granulosa without reference to the theca interna. Atresia in the bovine small antral ovarian follicle has been redefined into antral or basal atresia where cell death commences initially within antral or basal regions of the membrana granulosa, respectively. To examine cell death in the theca interna in the two types of atretic follicles, bovine ovaries were collected and processed for immunohistochemistry and light microscopy. Follicles were classified as healthy, antral atretic, or basal atretic. Follicle diameter was recorded and sections stained with lectin from Bandeiraea simplicifolia to identify endothelial cells or with an antibody to cytochrome P450 cholesterol side-chain cleavage to identify steroidogenic cells and combined with TUNEL labeling to identify dead cells. The numerical density of steroidogenic cells within the theca interna was significantly reduced (P < 0.001) in basal atretic follicles in comparison with other follicles. Cell death was greater in both endothelial cells (P < 0.05) and steroidogenic cells (P < 0.01) of the theca interna of basal atretic follicles compared with healthy and antral atretic follicles. Thus, we conclude that the theca interna is susceptible to cell death early in atresia, particularly in basal atretic follicles.
1 Supported by the National Health and Medical Research Council of Australia, The University of Adelaide, and the Clive and Vera Ramaciotti Foundations.
2 Correspondence: Raymond J. Rodgers, Department of Obstetrics and Gynaecology, The University of Adelaide, Adelaide, South Australia 5005, Australia. FAX: 61 8 8303 4099; ray.rodgers{at}adelaide.edu.au
Copyright © 2004 by the Society for the Study of Reproduction.