Effect of calcitonin gene-related peptide on the maturation of oocyte in vitro

Abstract

To explore the effect of calcitonin gene-related peptide (CGRP) on murine oocyte maturation. After injection of pregnant mare serum gonadotropin (PMSG, 10 U, i.p.) for 48 h, 6-week old female Kunming mice were killed, and the cumulus oocyte complexes (COCs) were collected from ovaries and inoculated in the culture plate by 30-40/hole. The COCs were treated with 4 concentrations of CGRP (0, 10(-10), 10(-9), and 10(-8) mol/L), and the germinal vesicle breakdown (GVBD) and polar body I (PBI) were examined. Human granulosa cells were also cultured with CGRP (0, 10(-10), 10(-9), 10(-8) mol/L) and levels of intracellular cyclic adenosine monophosphate (cAMP) were measured. Exogenous CGRP caused a decrease in GVBD and PBI in COCs, and an increase in cAMP levels in human granulosa cells in a concentration-dependent manner. CGRP can inhibit the oocyte maturation, which may be related to the increased content of cAMP in granulosa cells.