Ovarian cAMP and cGMP fluctuations in the hamster during the oestrous cycle.

Cyclic GMP, cAMP and total DNA levels were determined in whole hamster ovaries on each day of the 4-day cycle. Pro-oestrous ovaries were removed during the time of the preovulatory LH surge (confirmed by RIA). Cyclic AMP levels (pmol/mg DNA) were highest during pro-oestrous (1268.0 +/- 139 (s.e.m.)) and lowest during dioestrus 2 ( 266.9 +/- 22). Cyclic GMP (pmol/mg DNA levels were highest at dioestrus 2 (87.2 +/- 19) and lowest during oestrus (11.9 +/- 2). Similar patterns were obtained with total pmol/4 ovaries. However expressed, there was an inverse correlation of cAMP and cGMP at dioestrus 2 (P < 0.02) and pro-oestrus (P < 0.001). Cyclic GMP was inversely correlated with total DNA levels (P < 0.02) at oestrus and dioestrus 2.