Blood VolumeBlood PressurePressureBlood Pressure DeterminationHypertensionBlood Pressure Monitoring, AmbulatoryHeart RateAntihypertensive AgentsHemodynamicsHydrostatic PressurePlasma VolumeHypovolemiaCerebrovascular CirculationErythrocyte VolumeSystoleHypotensionBlood Pressure MonitorsRegional Blood FlowTime FactorsCardiac OutputHematocritVascular ResistanceIntracranial PressureReninDiastoleBlood Flow VelocityPlasma SubstitutesArterial PressurePulseMagnetic Resonance ImagingDogsVenous PressureKidneyRats, Inbred SHRIntraocular PressureCentral Venous PressureProspective StudiesTransducers, PressureSympathetic Nervous SystemCardiovascular SystemOxygenPressoreceptorsStroke VolumeReference ValuesBlood CirculationBaroreflexBody WeightBrainPostureReproducibility of ResultsLung Volume MeasurementsAnalysis of VarianceCircadian RhythmRats, Sprague-DawleyFluid ShiftsAtmospheric PressureRisk FactorsHemorrhageSphygmomanometersAngiotensin IIAir PressureCardiovascular DiseasesNorepinephrineFollow-Up StudiesCardiovascular Physiological PhenomenaHypertension, RenalSodiumSodium Chloride, DietarySodium ChlorideAldosteroneShock, HemorrhagicOxygen ConsumptionRegression AnalysisVentricular PressureHypotension, OrthostaticRats, Inbred WKYHemoglobinsTreatment OutcomeMonitoring, PhysiologicDiet, Sodium-RestrictedCarbon DioxideOrgan SizeSodium, DietaryDouble-Blind MethodHeartArteriesIsotonic SolutionsBody Mass IndexNatriuresisHemodilutionAngiotensin-Converting Enzyme InhibitorsCompliancePlethysmographySpectroscopy, Near-InfraredDose-Response Relationship, DrugRespirationLinear ModelsSupine PositionRenin-Angiotensin SystemDisease Models, Animal