Cyclic GMP concentration in ovarian tissue after administration of gonadotrophin to prepubertal rats

The weights, protein concentrations, and concentrations of cyclic AMP and cyclic GMP in the ovaries of prepubertal rats have been measured after induction of follicular growth by administration of pregnant mare serum gonadotrophin (PMSG). Three phases of ovarian growth, the follicular growth phase, the preovulatory phase and the luteal phase were investigated. Ovulation was induced by administration of human chorionic gonadotrophin (hCG). During the follicular phase, ovarian weight, protein content and the content of both cyclic AMP and cyclic GMP increased 2-3 days after administration of PMSG. Administration of hCG 65h after PMSG caused a rapid rise in the concentration of cyclic AMP but the concentration of cyclic GMP tended to fall. During the luteal phase the concentrations of both cyclic nucleotides decreased.