PUBLICATION
Adrenocorticotropic hormone suppresses gonadotropin-stimulated estradiol release from zebrafish ovarian follicles
- Authors
- Alsop, D., Ings, J.S., and Vijayan, M.M.
- ID
- ZDB-PUB-090807-10
- Date
- 2009
- Source
- PLoS One 4(7): e6463 (Journal)
- Registered Authors
- Keywords
- Hydrocortisone, Zebrafish, Traditional ACTH stimulation test, Ovarian follicles, Ovaries, Secretion, Fish physiology, Estradiol
- MeSH Terms
-
- Adrenocorticotropic Hormone/pharmacology*
- Animals
- Dose-Response Relationship, Drug
- Estradiol
- Female
- Gonadotropins/pharmacology*
- Hydrocortisone
- Ovarian Follicle/drug effects*
- Ovarian Follicle/metabolism
- Radioimmunoassay
- Zebrafish
- PubMed
- 19649243 Full text @ PLoS One
Citation
Alsop, D., Ings, J.S., and Vijayan, M.M. (2009) Adrenocorticotropic hormone suppresses gonadotropin-stimulated estradiol release from zebrafish ovarian follicles. PLoS One. 4(7):e6463.
Abstract
While stress is known to impact reproductive performance, the pathways involved are not entirely understood. Corticosteroid effects on the functioning of the hypothalamus-pituitary-gonadal axis are thought to be a key aspect of stress-mediated reproductive dysfunction. A vital component of the stress response is the pituitary secretion of adrenocorticotropic hormone (ACTH), which binds to the melanocortin 2 receptor (MC2R) in the adrenal glands and activates cortisol biosynthesis. We recently reported MC2R mRNA abundance in fish gonads leading to the hypothesis that ACTH may be directly involved in gonadal steroid modulation. Using zebrafish (Danio rerio) ovarian follicles, we tested the hypothesis that acute ACTH stimulation modulates cortisol and estradiol (E(2)) secretion. ACTH neither affected cortisol nor unstimulated E(2) release from ovarian follicles. However, ACTH suppressed human chorionic gonadotropin (hCG)-stimulated E(2) secretion in a dose-related manner, with a maximum decrease of 62% observed at 1 I.U. ACTH mL(-1). This effect of ACTH on E(2) release was not observed in the presence of either 8-bromo-cAMP or forskolin, suggesting that the mechanism(s) involved in steroid attenuation was upstream of adenylyl cyclase activation. Overall, our results suggest that a stress-induced rise in plasma ACTH levels may initiate a rapid down-regulation of acute stimulated E(2) biosynthesis in the zebrafish ovary, underscoring a novel physiological role for this pituitary peptide in modulating reproductive activity.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping