Interaction between cyclic nucleotide second messenger systems in murine Leydig cells.
Mouse Leydig cell androgen production can be acutely stimulated by atrial natriuretic factor (ANF) via cyclic guanosine 3',5'-monophosphate (cGMP). This stimulation can approach that seen with high concentrations of luteinizing hormone (LH) acting via cyclic adenosine 3',5'-monophosphate (cAMP). To assess the potential for synergistic interaction between LH/cAMP and ANF/cGMP Leydig cells were co-exposed to ANF and LH or ANF/cGMP and site/type-selective cAMP analogues. Co-exposure to 1 nM ANF and 1 ng/ml LH elicited a synergistic increase in androgen production. Both 500 microM 8-bromo-cGMP and ANF (1.0-2.5 nM) synergized with cAMP analogues selective for either of the two major isoenzymes of protein kinase A. Phosphodiesterase (PDE) inhibition was not involved as inclusion of a PDE inhibitor only augmented the response. It appears that ANF/cGMP may interact cooperatively with LH/cAMP in the stimulatory control of androgen production in the mouse Leydig cell and that the site of synergistic interaction may be the activation of the cAMP-dependent protein kinase.
Hipkin
R W
RW
Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada.
Moger
W H
WH
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D007985:Leydig Cells / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D051379:Mice; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D015290:Second Messenger Systems
D010726:Phosphodiesterase Inhibitors; D009320:Atrial Natriuretic Factor; D007986:Luteinizing Hormone; D000242:Cyclic AMP; D006152:Cyclic GMP