Steroidogenesis in porcine atretic follicles: loss of aromatase activity in isolated granulosa and theca.

Published

Journal Article

To evaluate the mechanisms involved in the reduction of estrogen concentrations in porcine follicular fluid during atresia, nonatretic and atretic follicles ranging from 4 to 7 mm in diameter were selected. Follicular fluid estrogen concentrations were 7-16-fold less in the atretic follicles. Isolated granulosa cells from atretic follicles demonstrated a significant reduction in aromatase activity and in follicle-stimulating hormone (FSH)-induced progesterone production in vitro compared to granulosa cells from nonatretic follicles. Isolated theca from atretic follicles also demonstrated a reduction in estrogen production. However, androgen concentrations were equivalent in the follicular fluid of atretic and nonatretic follicles, and theca from atretic follicles maintained testosterone and androstenedione production in vitro. The loss of thecal aromatase activity with atresia is not secondary to a reduction in FSH responsiveness, since FSH did not increase thecal progesterone production in vitro. Cell degeneration also does not account for the reduction in thecal estrogen production, since both androgen output in vitro and follicular fluid androgen concentrations were maintained. These data thus demonstrate that a mechanism other than reduced FSH responsiveness must account for the selective loss of thecal aromatase activity in this stage of atresia.

Full Text

Duke Authors

Cited Authors

  • Maxson, WS; Haney, AF; Schomberg, DW

Published Date

  • September 1985

Published In

Volume / Issue

  • 33 / 2

Start / End Page

  • 495 - 501

PubMed ID

  • 4041532

Pubmed Central ID

  • 4041532

International Standard Serial Number (ISSN)

  • 0006-3363

Digital Object Identifier (DOI)

  • 10.1095/biolreprod33.2.495

Language

  • eng

Conference Location

  • United States