C-type natriuretic peptide improved vitrified-warmed mouse cumulus oocyte complexes developmental competence.

Cryopreservation of cumulus oocyte complexes (COCs) is important for reproductive medicine. However, the vitrified-warmed COCs have lower maturation rate and subsequent developmental competence compared with fresh COCs. The present study was aimed to evaluate the effects of supplementation of the maturation medium with C-type natriuretic peptide (CNP) on the developmental competence of vitrified-warmed mouse COCs. Addition of CNP to the maturation medium improved the maturation rate and enhanced the developmental competence of vitrified-warmed mouse COCs. The reason may be that vitrified COCs led to a decline in cyclic guanosine monophosphate (cGMP) levels. Furthermore, addition of CNP to the maturation medium elevated cGMP levels of the vitrified-warmed COCs. In conclusion, cryopreservation-associated lower maturation rate and developmental competence of COCs may be ameliorated by CNP during maturation culture after warming.