AdenosineVasodilationReceptor, Adenosine A2AReceptor, Adenosine A1Adenosine DeaminaseReceptor, Adenosine A3Receptor, Adenosine A2BAdenosine KinaseReceptors, Adenosine A2Adenosine A2 Receptor AgonistsReceptors, Purinergic P1Adenosine A2 Receptor AntagonistsAdenosine A1 Receptor AntagonistsVasodilator AgentsAdenosine A1 Receptor AgonistsPurinergic P1 Receptor AntagonistsPurinergic P1 Receptor AgonistsXanthinesForearmAdenosine MonophosphateNitric OxideArteriolesEndothelium, VascularNitroprussideAdenosine-5'-(N-ethylcarboxamide)Regional Blood FlowTheophyllineAcetylcholineReceptors, PurinergicHyperemiaPhenethylaminesAdenosine A3 Receptor AntagonistsCoronary CirculationVascular ResistanceAdenosine A3 Receptor Agonists2-Chloroadenosineomega-N-MethylarginineBrachial ArteryCoronary VesselsNitroglycerinPhenylisopropyladenosineDose-Response Relationship, DrugInosine5'-NucleotidaseNitric Oxide SynthaseCyclic AMPVasoconstrictionEnzyme InhibitorsNG-Nitroarginine Methyl EsterBlood PressureDogsBlood Flow VelocityHemodynamicsDipyridamoleMicrocirculationAdenosine TriphosphatasesTubercidinAdenine NucleotidesLaser-Doppler FlowmetryRats, Sprague-DawleyVasomotor SystemEndothelium-Dependent Relaxing FactorsMesenteric ArteriesIndomethacinBradykininNitroarginineVasoconstrictor AgentsPurinesNitric Oxide Synthase Type IIINucleoside DeaminasesPia MaterInfusions, Intra-ArterialCoformycinArginineHeart RatePlethysmographyRats, WistarGlyburideBiological FactorsAminophyllineTheobromineAnoxiaMuscle, Smooth, VascularCyclooxygenase InhibitorsPapaverinePotassium ChannelsSkinPerfusionTriazinesPentostatinPulmonary CirculationAdenosine PhosphosulfatePotassium Channel BlockersBretylium TosylateTime FactorsSwineNitric Oxide DonorsArteriesCyclic GMPNorepinephrine