Interactions Between Androgen and Growth Factors in Granulosa Cell Subtypes of Porcine Antral Follicles
Androgens acting via the androgen receptor (AR) have been implicated in regulation of folliculogenesis in many animal species. These effects are possibly mediated via enhancement of FSH and/or insulin-like growth factor (IGF)-I activity in granulosa cells, which contain high levels of AR protein. We...
Saved in:
Published in | Biology of reproduction Vol. 71; no. 1; pp. 45 - 52 |
---|---|
Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Madison, WI
Society for the Study of Reproduction
01.07.2004
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Androgens acting via the androgen receptor (AR) have been implicated in regulation of folliculogenesis in many animal species.
These effects are possibly mediated via enhancement of FSH and/or insulin-like growth factor (IGF)-I activity in granulosa
cells, which contain high levels of AR protein. We examined the in vitro effect of dihydrotestosterone (DHT) on DNA synthesis
and progesterone secretion by follicular cells in response to FSH and IGF-I, alone or in combination. Cells from separate
pools of 1- to 3-mm and 3- to 5-mm antral follicles were aspirated from gilt ovaries and fractioned into mural granulosa cells
(MGCs) and cumulus-oocyte complexes (COCs) for subsequent cell culture. Androgen alone or with any combination of mitogen
had minimal effect on proliferative and no effect on steroidogenic responses of MGCs from 3- to 5-mm antral follicles. Conversely,
in MGCs from 1- to 3-mm follicles, DHT significantly enhanced IFG-I-stimulated proliferation and had variable influence on
progesterone secretion. The effects of DHT on proliferative responses of COCs were also dependent on follicle size: DHT significantly
augmented either IGF-I-stimulated proliferation (1- to 3-mm follicles) or FSH-stimulated proliferation (3- to 5-mm follicles).
However, the steroidogenic responses of all COCs were identical, whereby DHT significantly suppressed progesterone secretion,
predominantly in the presence of FSH. Addition of an AR antagonist, hydroxyflutamide, generally reversed the proliferative
responses invoked by DHT but not the steroidogenic responses. We conclude that androgen-receptor-mediated activity in granulosa
cells of antral follicles is dependent on follicle size, is influenced by proximity of cells to the oocyte, and possibly involves
both classic and nonclassic steroid mechanisms. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0006-3363 1529-7268 |
DOI: | 10.1095/biolreprod.103.026484 |