Steroidogenesis in Porcine Atretic Follicles: Loss of Aromatase Activity in Isolated Granulosa and Theca1
| Autor: | W. S. Maxson, David W. Schomberg, Arthur F. Haney |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
endocrine system
medicine.medical_specialty biology medicine.drug_class Cell Biology General Medicine Androgen Follicular fluid Endocrinology medicine.anatomical_structure Reproductive Medicine Estrogen Theca Internal medicine medicine biology.protein Androstenedione Aromatase Ovarian follicle hormones hormone substitutes and hormone antagonists Testosterone |
| Zdroj: | Biology of Reproduction. 33:495-501 |
| ISSN: | 1529-7268 0006-3363 |
| DOI: | 10.1095/biolreprod33.2.495 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|