AdenosineCoronary CirculationReceptor, Adenosine A2AReceptor, Adenosine A1Adenosine DeaminaseReceptor, Adenosine A3Receptor, Adenosine A2BAdenosine KinaseReceptors, Adenosine A2Adenosine A2 Receptor AgonistsAdenosine A2 Receptor AntagonistsReceptors, Purinergic P1Adenosine A1 Receptor AntagonistsAdenosine A1 Receptor AgonistsAdministration, OralPurinergic P1 Receptor AntagonistsXanthinesPurinergic P1 Receptor AgonistsAdenosine MonophosphateAdenosine-5'-(N-ethylcarboxamide)TheophyllineAdenosine A3 Receptor AntagonistsReceptors, PurinergicDose-Response Relationship, DrugAdenosine A3 Receptor AgonistsPhenethylamines2-ChloroadenosinePhenylisopropyladenosineInosineRats, Sprague-Dawley5'-Nucleotidase