Cardiovascular SystemHeart RateBlood PressureCardiovascular Physiological PhenomenaHemodynamicsCisterna MagnaCardiac OutputVascular ResistanceDose-Response Relationship, DrugHypotensionConsciousnessDogsAngiotensin AmideMedetomidineAnesthesiaNoise, Transportationgamma-MSHRats, Inbred SHRDrug InteractionsInjections, IntravenousInjections, IntraventricularBradycardiaNasal DecongestantsEphedrinePipecuroniumHypoxisSympathomimeticsPropranololCentral Venous PressureCardiovascular DiseasesParticulate MatterRespirationAnesthesia, IntratrachealPancuroniumCardiotonic AgentsHalothaneAnesthesia, InhalationClonidineHeartNorepinephrineHypertensionMyocardial ContractionNitrous OxideCross CirculationTachycardiaIsofluraneDouble-Blind MethodMedulla OblongataHelichrysumVasodilationFelypressinRats, Sprague-DawleyChlorisondamineCardiovascular AgentsVasodilator AgentsAntihypertensive AgentsAdrenergic beta-AntagonistsAircraftSolitary NucleusXylazineTelemetryInfusions, IntravenousPhentolamineAdrenergic alpha-AntagonistsCyclobutanesPhenylephrineRats, WistarFelodipineAdrenergic alpha-AgonistsCombretumRailroadsTime FactorsXamoterolElectrocardiographyCross-Over StudiesNeuromuscular Blocking AgentsPyridazinesGanglionic BlockersCatecholaminesSympathetic Nervous SystemPropanolaminesMidazolamRubiaceaeChlorpheniramineEpinephrineInjectionsAutomobilesVasopressinsPiperidinesAir PollutantsMecamylamineVasoconstrictor AgentsRegional Blood FlowAutonomic Nervous SystemDecerebrate StateMicroinjectionsHypnotics and SedativesNeuromuscular Nondepolarizing AgentsIsoquinolinesAnesthetics, Combined