Concentrations of cyclic AMP in rabbit ovarian tissue during the preovulatory period and pseudopregnancy after induction of ovulation by administration of human chorionic gonadotrophin.

Concentrations of cyclic AMP were measured in rabbit ovaries at various times after injection of an ovulatory dose of human chorionic gonadotrophin (HCG). A biphasic increase in cyclic AMP concentration occurred during the preovulatory period, with peaks 30 min and 3-4 h after HCG injection. Concentrations of cyclic AMP had returned to those observed in ovaries of control oestrous animals before the onset of ovulation 10-12 h after administration of HCG, and remained low throughout the period of pseudopregnancy. Concentrations of cyclic AMP in the newly formed and developing corpora lutea were similar to the concentrations observed in the remainder of the tissue during this period. No significant increase in cyclic AMP concentration was observed 7-9 days after initiation of ovulation. Concentrations of ATP were also investigated during the preovulatory period. The dose-response relationship of HCG to cyclic AMP production in oestrous rabbit ovaries was investigated.