HypotensionHypotension, ControlledHypotension, OrthostaticIntracranial HypotensionBlood PressurePost-Exercise HypotensionTrimethaphanBradycardiaHeart RateEphedrineAnesthesia, SpinalAnesthesia, ObstetricalHemodynamicsAutonomic Nervous System DiseasesShockAnesthesiaBasic-Leucine Zipper Transcription FactorsShock, SepticMidodrineCerebrovascular CirculationVascular ResistanceNitroprussideOcular HypotensionCardiac OutputH-Y AntigenHypovolemiaFerricyanidesSyncopeRNA, Small CytoplasmicShy-Drager SyndromePure Autonomic FailureBlood Patch, EpiduralPostureIntraoperative ComplicationsSubdural EffusionTilt-Table TestIntracranial PressureVasoconstrictor AgentsHypocotylShock, HemorrhagicCardiovascular SystemFluid TherapyHemorrhageSympathetic Nervous SystemDogsBlood VolumeTime FactorsCesarean SectionMethyldopaAnesthesia, EpiduralAutonomic Nervous SystemBionicsIsotonic SolutionsPressoreceptorsPhenylephrineNorepinephrineRegional Blood FlowDose-Response Relationship, DrugBaroreflexAntihypertensive AgentsPhytochromeSplanchnic CirculationClonidineVasodilationLypressinPlasma SubstitutesArabidopsis ProteinsSyncope, VasovagalInfusions, IntravenousRats, Sprague-DawleyFludrocortisoneValsalva ManeuverArabidopsisRenal DialysisHydralazineIsofluraneInjections, IntravenousBupivacaineReflexSupine PositionProspective StudiesAnesthesia, GeneralHypertensionVasodilator AgentsHeat StrokeAnaphylaxisTachycardiaMonitoring, IntraoperativeResuscitationBlood Volume DeterminationArterial PressureHomeostasisBlood Gas AnalysisLightNitric OxideBrainTreatment OutcomeMyelographyPlasma VolumeHalothane