Role of cyclic AMP in stimulation-evoked release of 3H-noradrenaline from rabbit isolated ear artery.
The possible involvement of cyclic AMP in the stimulation-evoked 3H-overflow from rabbit isolated ear artery preloaded with 3H-noradrenaline was studied. Cyclic AMP (10(-5)-3 x 10(-4)M), 8-bromo-cyclic AMP (3 x 10(-4)M) and adenosine (10(-5)-3 x 10(-4)M) enhanced stimulation-evoked 3H-overflow. Dibutyryl-cyclic AMP (10(-5)-3 x 10(-4)M) had no effect. Theophylline (3 x 10(-5)M) and the phosphodiesterase inhibitor AH 21-132 (3 x 10(-5)M) did not alter the enhancement of 3H-overflow caused by either cyclic AMP or adenosine. Forskolin (3 x 10(-6)M) and the phosphodiesterase inhibitors ICI 63 197 (10(-4)M) and AH 21-132 (3 x 10(-6)-3 x 10(-5)M) increased stimulation-evoked 3H-overflow. Forskolin (10(-6)M) enhanced the effect of ICI 63 197 (3 x 10(-5)M) but it did not alter the effect of AH 21-132. It is concluded that cyclic AMP is involved in the stimulation-evoked release of noradrenaline from postganglionic sympathetic nerves in the rabbit ear artery.
Abrahamsen
J
J
Department of Pharmacology, School of Medicine, Odense University, Denmark.
Nedergaard
O A
OA
D000241:Adenosine / Q000494:pharmacology; D000818:Animals; D001158:Arteries / Q000378:metabolism; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000502:physiology*; D004423:Ear / Q000098:blood supply*; D004558:Electric Stimulation; D005260:Female; D008297:Male; D009287:Naphthyridines / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology; D011817:Rabbits; D013806:Theophylline / Q000494:pharmacology; D014316:Tritium
D009287:Naphthyridines; D010726:Phosphodiesterase Inhibitors; D011743:Pyrimidines; C006313:ICI 63197; D014316:Tritium; D005576:Colforsin; C044843:AH 21-132; D013806:Theophylline; D000242:Cyclic AMP; D000241:Adenosine; D009638:Norepinephrine