| Autor: |
Chouzouris TM; Department of Obstetrics and Reproduction,Veterinary Faculty,School of Health Sciences,Karditsa,University of Thessaly,Greece., Dovolou E; Department of Obstetrics and Reproduction,Veterinary Faculty,School of Health Sciences,Karditsa,University of Thessaly,Greece., Krania F; Department of Obstetrics and Reproduction,Veterinary Faculty,School of Health Sciences,Karditsa,University of Thessaly,Greece., Pappas IS; Department of Pharmacology,Veterinary Faculty,School of Health Sciences,Karditsa,University of Thessaly,Greece., Dafopoulos K; Department of Obstetrics and Gynecology,Faculty of Medicine,School of Health Sciences,Larissa,University of Thessaly,Greece., Messinis IE; Department of Obstetrics and Gynecology,Faculty of Medicine,School of Health Sciences,Larissa,University of Thessaly,Greece., Anifandis G; Department of Obstetrics and Gynecology,Faculty of Medicine,School of Health Sciences,Larissa,University of Thessaly,Greece., Amiridis GS; PO Box 199,43100 Karditsa,Greece. |
| Abstrakt: |
The purpose of this study was to investigate the possible molecular pathways through which ghrelin accelerates in vitro oocyte maturation. Bovine cumulus-oocyte complexes (COCs), after 18 or 24 h maturation in the absence or the presence of 800 pg ml-1 of acylated ghrelin were either assessed for nuclear maturation or underwent in vitro fertilization in standard media and putative zygotes were cultured in vitro for 8 days. In a subset of COCs the levels of phosphorylated Akt1 and ERK1/2 (MAPK1/3) were assessed at the 0th, 6th, 10th, 18th and 24th hours of in vitro maturation (IVM). At 18 and 24 h no difference existed in the proportion of matured oocytes in the ghrelin-treated group, while in the control group more (P < 0.05) matured oocyte were found at 24 h. Oocyte maturation for 24 h in the presence of ghrelin resulted in substantially reduced (P < 0.05) blastocyst yield(16.3%) in comparison with that obtained after 18 h (30.0%) or to both control groups (29.3% and 26.9%, for 18 and 24 h in maturation, respectively). Ghrelin-treated oocytes expressed lower Akt1 phosphorylation rate at the 10th hour of IVM, and higher ERK1/2 at the 6th and 10th hours of IVM compared with controls. In cumulus cells, at the 18th and 24th hours of IVM Akt1 phosphorylation rate was higher in ghrelin-treated oocytes. Our results imply that ghrelin acts in a different time-dependent manner on bovine oocytes and cumulus cells modulating Akt1 and ERK1/2 phosphorylation, which brings about acceleration of the oocyte maturation process. |
