IsofluraneAnesthetics, InhalationHalothaneAnesthesia, InhalationEnfluraneMethyl EthersAnestheticsNitrous OxideEthersAnesthesiaAnesthetics, IntravenousPropofolDogsAnesthetics, GeneralHemodynamicsFentanylAnesthesia, GeneralDose-Response Relationship, DrugXenonAnesthesia Recovery PeriodRats, Sprague-DawleyDrug InteractionsDepression, ChemicalMethoxyfluraneTime FactorsBlood Gas AnalysisThiopentalElectroencephalographyDrug Administration SchedulePulmonary AlveoliIschemic Preconditioning, MyocardialBlood PressurePentobarbitalAnesthetics, CombinedRadiation DosageEtherLethal Dose 50Heart RateKetamineHeartIschemic Preconditioning