TrazodoneCyclic GMPNitric OxideNitric Oxide SynthaseNitric Oxide Synthase Type IINitric Oxide DonorsDibutyryl Cyclic GMPNitric Oxide Synthase Type IIINitric Oxide Synthase Type IGuanylate CyclaseNG-Nitroarginine Methyl EsterArginineNitroprussideomega-N-MethylargininePurinones3',5'-Cyclic-GMP PhosphodiesterasesNitritesS-Nitroso-N-AcetylpenicillamineEnzyme InhibitorsPenicillamineMethylene BlueNitratesAmino Acid OxidoreductasesOxadiazolesEndothelium, VascularMolsidomineNitrogen OxidesCyclic AMPNitroarginineVasodilationCyclic GMP-Dependent Protein KinasesMuscle RelaxationVasodilator AgentsS-NitrosoglutathioneNucleotides, CyclicOxidesAtrial Natriuretic FactorDose-Response Relationship, DrugCells, CulturedRats, Sprague-DawleyRats, Wistar