Resumen de Secreción de melatonina por las células del cúmulus ovinas y posible acción de esta hormona sobre los daños en el DNA durante la maduración in vitro
Adriana Casao Gascón, Rosaura Pérez Pe, Fernando Forcada Miranda, José Alfonso Abecia Martínez, José Álvaro Cebrián Pérez, María Teresa Muiño Blanco
Melatonin is secreted by the pineal gland from serotonin, although recent works suggest that other tissues, including ovarian cumulus cells, can also secret this hormone. In order to determine whether sheep cumulus cells can synthetize melatonin, we assessed the presence of serotonin N-acetyltransferase (AANAT) and hydroxyindol-O methyltransferase (HIOMT) in protein extracts from ovine cumulus cells after in vitromaturation (IVM). Western blotting showed a 23 kDa band, compatible with AANAT and a 68 kDa, compatible with HIOMT. We also determined if the melatonin effect on inhibition of DNA damage of cumulus cells during IVM is mediated by the binding to its receptors. We used melatonin receptor antagonists (4P-PDOP and luzindole) and melatonin during IVM. DNA damage was assessed by the TUNEL technique. DNA damage of luzindole-mature cells was significantly higher when compared with the other groups (P<0.05), but there were no significant differences between melatonin or 4P-PDOP and control groups. In conclusion, this study shows that sheep cumulus cells have the ability to synthesize melatonin, and that the DNA damage protective effect during IVM might be exerted by binding to MT1 receptors.
