AdenosineReceptor, Adenosine A2AReceptor, Adenosine A1HyperhomocysteinemiaAdenosine DeaminaseVitamin B 12Receptor, Adenosine A3Folic AcidReceptor, Adenosine A2BAdenosine KinaseReceptors, Adenosine A2Adenosine A2 Receptor AgonistsAdenosine A2 Receptor AntagonistsReceptors, Purinergic P1Adenosine A1 Receptor AntagonistsHomocystineCystathionine beta-SynthaseMethylenetetrahydrofolate Reductase (NADPH2)Adenosine A1 Receptor AgonistsMethionineVitamin B ComplexPurinergic P1 Receptor AntagonistsVitamin B 6XanthinesPurinergic P1 Receptor AgonistsBetaine-Homocysteine S-MethyltransferaseAdenosine MonophosphateCystathionineS-Adenosylhomocysteine5-Methyltetrahydrofolate-Homocysteine S-MethyltransferaseAdenosine-5'-(N-ethylcarboxamide)HomocystinuriaOxidoreductases Acting on CH-NH Group DonorsTheophyllineVitamin B 12 DeficiencyAdenosine A3 Receptor AntagonistsFolic Acid DeficiencyReceptors, PurinergicTubercidinAdenosine A3 Receptor AgonistsS-AdenosylmethionineInosine2-ChloroadenosineMethylmalonic AcidPhenethylaminesPhenylisopropyladenosineBetaine5'-NucleotidaseAdenosylhomocysteinaseHomocysteine S-MethyltransferasePyridoxineCyclic AMPAdenosine TriphosphatasesAdenine Nucleotides5,10-Methylenetetrahydrofolate Reductase (FADH2)Glycine N-MethyltransferaseCysteineTetrahydrofolatesDose-Response Relationship, DrugDietary SupplementsRisk FactorsNucleoside DeaminasesCoformycinVitamin B DeficiencyDipyridamoleTranscobalaminsMethylationTheobromineKineticsVitamin B 6 DeficiencyPyridoxal PhosphatePentostatinCells, CulturedPurinesAdenosine PhosphosulfateSarcosineAdenineBiological MarkersDeoxyadenosinesCystathionine gamma-LyaseGenotypeEndothelium, VascularVasodilator AgentsTime FactorsThioinosineTriazinesRats, Sprague-DawleyCardiovascular DiseasesPolymorphism, GeneticLipotropic AgentsHypoxanthinesVascular DiseasesHypoxanthineCase-Control StudiesMethyltransferasesChromatography, High Pressure LiquidPurinergic AntagonistsSulfhydryl CompoundsFastingReference Values