“Endocannabinoids have been recognized as mediators of practically all reproductive events in mammals. However, little is known about the role of this system in oocyte maturation.
In a mouse model, we observed that activation of the cannabinoid receptor (CB)1during in vitro oocyte maturation modulated the phosphorylation status of Akt and ERK1/2 and enhanced the subsequent embryo production. In the absence of the CB1 receptor, in vivo oocyte maturation was impaired and embryo development delayed. The CB2receptor was unable to rescue these effects. Finally, we confirmed abnormal oocyte maturation rather than impaired embryonic transport through the oviduct in CB1 knockouts.
Our data suggest that cannabinoid agonists may be useful in vitro maturation supplements. For in vitro fertilization patients intolerant to gonadotropins, this could be a promising and only option.”