title: Involvement of cAMP in modulation of noradrenaline release in the human pulmonary artery.
abstract: After incubation with 3H-noradrenaline, strips of human pulmonary arteries from patients undergoing surgery for lung tumour were superfused with physiological salt solution containing cocaine and corticosterone. Forskolin, AH 21-132 (a cAMP phosphodiesterase inhibitor), 8-Br-cAMP and isoprenaline did not affect the basal tritium efflux from the strips, but produced a concentration-dependent facilitation of the tritium overflow evoked by transmural electrical stimulation (2 Hz). The facilitatory effect of isoprenaline was potentiated by forskolin which produced a shift to the left of the concentration-response curve of isoprenaline. It is concluded that cAMP plays a role in the modulation of noradrenaline release in the human pulmonary artery and that presynaptic beta-adrenoceptors appear to be coupled to an adenylate cyclase in the sympathetic nerve terminals.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors; D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism; D000328:Adult; D000368:Aged; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000502:physiology*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009287:Naphthyridines / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism*; D011651:Pulmonary Artery / Q000378:metabolism
chemical_list: D009287:Naphthyridines; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; C044843:AH 21-132; D000242:Cyclic AMP; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D000262:Adenylyl Cyclases; D007545:Isoproterenol; D009638:Norepinephrine