P-209 Implication of delta opioid receptor in the in vitro maturation of oocytes and its effects on subsequent fertilization and embryo development in mice

Abstract Study question Could opiods modulate in vitro maturation of oocyte and improve fertilization rates? Summary answer Delta opioid receptor was present mice oocytes, changing its expression pattern depending on the stage helping oocytes to reach blastocyst stage. What is known already The molecular mechanisms responsible for are not completely understood different molecules have been reported be implicated as modulators this process. endogenous peptides could interesting candidates because they involved regulation reproductive physiology at multiple sites. When those receptors activated, adenylyl cyclase inhibited, thus reducing cyclic AMP blocking PKA. Moreover, opioids also able activate proteins maturation. There evidence suggesting a role during signaling exerted by similar that necessary meiosis resumption. design, size, duration Immature cumulus–oocyte complexes (COCs) from female 8 10 week old WT (C57BL/6xCBA) were retrieved after EGF stimulation. Mouse culture performed. In grown their corresponding cumulus (CC) granulosa cells (GC) classified germinal vesicle (GV), metaphase 1 (MI) 2 (MII). Participants/materials, setting, methods presence DOR analysed each qRT-PCR immunocytochemistry. AKT MAPK signalling pathway (ERK 1/2) studied Similarly, COCs matured absence DPDPE naltrindole various concentrations. After IVM, fertilisation (IVF) performed development observed until reached, analysing embryo production percentages (p < 0.05). Main results chance Our findings showed OPRD1 cells, evaluation RT-PCR examination immunohistochemical (IHC) staining revealed transcript Oprd1 gene stages mouse oocyte's maturation, well moment extraction ovary. obtained compared with cerebral cortex positive control. expected 482 bp fragment detected whereas MI MII signal lower. Immunofluorescence analysis protein but, localization differed Furthermore, selective delta agonist DPDPE, modulating PI3K/Akt pathways, helped Finally, we examined effect subsequent blocked antagonist naltrindole. Limitations, reasons caution Although higher rates blastocysts, quality these embryos still needs transferred recipient females evaluate offspring. Wider implications study has clinical improvement techniques (IVM). possible therapeutic target medium, it actual reproduction assisted techniques. Trial registration number applicable