Back to Search
Start Over
Regulation of aryl hydrocarbon receptor activity in porcine cumulus–oocyte complexes in physiological and toxicological conditions: the role of follicular fluid
- Source :
- Reproduction. 133:887-897
- Publication Year :
- 2007
- Publisher :
- Bioscientifica, 2007.
-
Abstract
- The arylhydrocarbon receptor (AhR) mediates the adverse effects of dioxin-like compounds. However, it has also been reported that the AhR may exert a role in ovarian physiology. In the present study, porcine cumulus–oocyte complexes (COCs) were maturedin vitroin the presence of 10% follicular fluid. Expression of AhR and its partner, AhR nuclear translocator occurs in immature COCs. Afterin vitromaturation (IVM), an up-regulation of AhR and cytochrome P450 1A1 (CYP1A1; the main AhR-target gene) was observed. To explore the role of the AhR during IVM, we exposed the COCs to 50 μM β-napthoflavone (βNF). The treatment induced a marked up-regulation of CYP1A1 mRNA, indicating both constitutive and inducible AhR activity. However, in contrast to what was observed in other cell types, no sign of toxicity was observed in COCs. To investigate if components of porcine follicular fluid may exert a protective role against AhR ligands, we exposed porcine COCs to βNF, in the absence of follicular fluid. In these conditions, a marked decrease in the percentage of matured oocytes, concomitant with an increase in oocyte degeneration, was observed. Furthermore, βNF increased apoptosis in cumulus cells in the absence of follicular fluid, whereas βNF has no effects when COCs were treated in the presence of porcine follicular fluid (pFF). In conclusion, these results suggest the presence of unknown endogenous AhR-ligand(s) during porcine IVM and that a dysregulation of this mechanism may result in ovotoxicity by inducing apoptosis in cumulus cells. However, this phenomenon is interrupted by the presence of follicular fluid, indicating a putative protective role for follicular fluid components against exogenous insults.
- Subjects :
- endocrine system
Embryology
medicine.medical_specialty
Cell type
Aryl hydrocarbon receptor nuclear translocator
Swine
Blotting, Western
Apoptosis
Fertilization in Vitro
Biology
Andrology
Oogenesis
Endocrinology
Ovarian Follicle
beta-Naphthoflavone
Internal medicine
Cytochrome P-450 CYP1A1
In Situ Nick-End Labeling
medicine
Animals
RNA, Messenger
Receptor
Aryl hydrocarbon receptor activity
Reverse Transcriptase Polymerase Chain Reaction
Aryl Hydrocarbon Receptor Nuclear Translocator
Obstetrics and Gynecology
Cell Biology
respiratory system
Oocyte
Follicular fluid
Follicular Fluid
In vitro maturation
Meiosis
medicine.anatomical_structure
Receptors, Aryl Hydrocarbon
Reproductive Medicine
Oocytes
Female
Subjects
Details
- ISSN :
- 17417899 and 14701626
- Volume :
- 133
- Database :
- OpenAIRE
- Journal :
- Reproduction
- Accession number :
- edsair.doi.dedup.....b9637c4cc02f8e38e0618dac194cc60f