ArteriolesPia MaterVasodilationVenulesRetinal ArteryVasoconstrictionMicrocirculationVasodilator AgentsMuscle, Smooth, VascularCheekNitric OxideEndothelium, VascularJuxtaglomerular ApparatusMicroscopy, VideoVasomotor SystemVasoconstrictor AgentsRats, Sprague-DawleyCapillariesAcetylcholineNitroarginineCerebral ArteriesNitroprussideMesoporphyrinsNG-Nitroarginine Methyl EsterRegional Blood FlowRenal CirculationCoronary VesselsArteriesNitric Oxide SynthaseSwine, MiniatureVascular ResistanceBlood PressureEnzyme InhibitorsMesocricetusMuscle, SkeletalHydronephrosisRetinal VesselsNitric Oxide Synthase Type IIIKidney GlomerulusAdenosineMuscle TonusIndomethacinRats, Inbred WKYRats, Inbred SHRNorepinephrineSwineDose-Response Relationship, DrugBlood Flow VelocityKidneyPotassium ChlorideRats, WistarBradykininHydrazines15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic AcidMicrovesselsAngiotensin IIRetinal VeinCyclic N-OxidesCyclooxygenase InhibitorsProstaglandinsGlyburideCorrosion CastingStress, MechanicalPotassium Channel BlockersMesenteryPimozidePerfusion