Concentration of cyclic AMP in rabbit ovaries in the preovulatory period after administration of luteinizing hormone or human chorionic gonadotrophin.

Ovarian adenosine 3'-5'-monophosphate (cAMP) concentrations were determined in untreated female rabbits and in those sacrificed at various times (0.5-6.0 h) after administration of luteinizing hormone (LH, 50 micrograms) or human chorionic gonadotrophin (hCG, 100 IU). Both LH and hCG caused a rapid increase in ovarian cAMP concentrations within 0.5 h. After LH stimulation the elevated levels declined rapidly and by 2 h they were almost back to control levels. In the hCG-treated animals the decline in ovarian cAMP from the initial peak concentrations was much more gradual and the levels were significantly higher than control even at 6 h. The different response to the two gonadotrophins is discussed in relation to the physiologic importance earlier attributed to the prolonged elevation of cAMP in rabbit ovaries after stimulation with hCG.