Catecholamine stimulation of cyclic AMP and progesterone production in rat corpora lutea of different ages

Abstract

In vitro effects of catecholamines (adrenaline and noradrenaline) and adrenergic antagonists on adenosine 3',5'-cyclic monophosphate (cAMP) and progesterone production by rat corpora lutea (CL) of different ages (1-8 days old) were studied. To obtain defined ages of CL a pregnant mare's serum gonadotrophin (PMSG) model was used. The effect of catecholamines on cAMP decreased with luteal age while the effect on progesterone production was maximal on 5 day old CL. The beta-blocker propranolol inhibited the effects of catecholamines in concentrations around 10-(5) M. The effects of LH could only be inhibited with higher doses of propranolol known to exert unspecific effects. These results support the theory that LH and catecholamine effects on rat corpora lutea are mediated through different receptors.