title: Effect of 8-sulfophenyl theophylline on endogenous noradrenaline release from sympathetic nerves of the rabbit ear artery.
abstract: 1. The release of endogenous noradrenaline (NA) and adenyl purine (ATP, ADP, AMP and adenosine) from the rabbit ear artery, evoked by electrical stimulation (ES; 16 Hz), was examined. 2. ES evoked a significant release of NA and purine; the ratio of the amount of total purine released to NA released was approximately 180 on a molar base. 3. ES-evoked purine release was significantly reduced by the denudation of the endothelium and abolished by the alpha 1-adrenoceptor antagonist, prazosin (1 mumol/L). 4. ES-evoked NA release was significantly reduced by a P1-purinoceptor antagonist, 8-sulfophenyl theophylline (8SPT). Purine release was slightly reduced by 8SPT. 5. These results suggest that endogenous NA released by ES results in the release of a large amount of purine, which may, in turn, increase the release of NA by acting on prejunctional purinoceptors on sympathetic nerve terminals.
authors.affiliation: Department of Pharmacology, Meiji College of Pharmacy, Tokyo, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Ishii
authors.forename: K
authors.initials: K
authors.lastname: Shinozuka
authors.forename: M
authors.initials: M
authors.lastname: Kunitomo
authors.forename: T
authors.initials: T
authors.lastname: Hashimoto
authors.forename: K
authors.initials: K
authors.lastname: Takeuchi
mesh_terms: D000818:Animals; D001158:Arteries / Q000294:innervation*; D004423:Ear / Q000098:blood supply*; D004558:Electric Stimulation / Q000379:methods; D009638:Norepinephrine / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010525:Peripheral Nerves / Q000187:drug effects / Q000378:metabolism*; D011224:Prazosin / Q000494:pharmacology; D058915:Purinergic P1 Receptor Antagonists; D011817:Rabbits; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000378:metabolism*; D013806:Theophylline / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D058915:Purinergic P1 Receptor Antagonists; C031433:8-(4-sulfophenyl)theophylline; D013806:Theophylline; D009638:Norepinephrine; D011224:Prazosin