title: Effects of norepinephrine on cyclic nucleotide levels in the ductus deferens of the rat.
abstract: The effect of 1-norepinephrine on cyclic nucleotide levels was studied in rat ductus deferens. Norepinephrine (0.01-0.3 mM) increased cyclic AMP and cyclic GMP levels in a concentration-dependent manner. Cyclic GMP was increased by about two-fold and cyclic AMP by 30%-40% by 0.1 mM norepinephrine after 3 min. Phenylephrine (0.1 mM) increased cyclic GMP levels about twofold without affecting cyclic AMP. Cyclic GMP was maximally increased by norepinephrine or phenylephrine after 3-10 min, but was not significantly changed after 20 sec, when contraction was fully developed. Atropine did not affect the norepinephrine-induced changes in cyclic nucleotide levels; phentolamine blocked the effect of norepinephrine on cyclic GMP, and propanolol blocked that on cyclic AMP. These findings indicate that in the ductus deferens alpha-adrenergic receptors are involved in the effect of catecholamines on cyclic GMP, and beta-adrenergic receptors are involved in the effect on cyclic AMP levels. The presence of Ca-2+ was required for the effect of norepinephrine on cyclic GMP, but not on cyclic AMP.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D000242:Cyclic AMP / Q000032:analysis*; D006152:Cyclic GMP / Q000032:analysis*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology*; D010646:Phentolamine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011941:Receptors, Adrenergic; D013268:Stimulation, Chemical; D013997:Time Factors; D014649:Vas Deferens / Q000032:analysis / Q000187:drug effects* / Q000201:enzymology; D014970:Xanthines / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D010726:Phosphodiesterase Inhibitors; D011941:Receptors, Adrenergic; D014970:Xanthines; D010656:Phenylephrine; D001285:Atropine; D011433:Propranolol; D000242:Cyclic AMP; D006152:Cyclic GMP; D000109:Acetylcholine; D002118:Calcium; D009638:Norepinephrine; D010646:Phentolamine