ATP as a sympathetic neurotransmitter

摘要: ATP has been shown to be a sympathetic neurotransmitter in blood vessels. However, its relative importance influenced by the experimental conditions employed such as alteration of vascular tone. Thus main aim was raise tone preparations and further examine neurotransmission these preparations. Porcine whole mesenteries were perfused with physiological buffer changes pressure recorded or different sized mesenteric arteries isolated set up for isometric recording. Responses electrical field stimulation (EFS) obtained under basal raised induced U46619, thromboxane A2 mimetic. The nature neurotransmitters involved mediation electrically-evoked responses assessed using an α1-adrenoceptor antagonist, prazosin and/or P2X receptor desensitizing agent, α,β-methyleneATP, α2-adrenoceptor RX811059 neuropeptide Y Y1 antagonist BIBP3226. In separate experiments, nerve investigated rat small pressurized 90 mmHg. effects selective YM-12617, P2X1 NF-449, on response determined. Under contractile porcine bed exclusively mediated noradrenaline (NA) since they inhibited prazosin. tone, enhanced role evident sensitive α,β-methyleneATP. Responses exogenous NA α,β-methyleneATP also at indicating postjunctional mechanism enhancement. Nifedipine attenuated EFS suggesting possible L-type calcium channels responses. pressurised vasocontractile YM-12617 that Raising U46619 response; both NF-449. The present study supports observation becomes more important contrast when is absent. predominates became evident.