B:Uses:l.Hypotension:2.Earlyphaseofneurogenicshock3.Uppergastrointestinaltractbleeding:It contracts blood vessels of esophagus and stomachand stopsthebleeding
B:Uses: 1.Hypotension: 2.Early phase of neurogenic shock 3.Upper gastrointestinal tract bleeding: It contracts blood vessels of esophagus and stomach, and stops the bleeding
III.β ReceptorAgonists-Isoprenaline(Isoproterenol)PharmacologicaleffectsL.Cardiovascularsystemβ, receptors :increases cardiac contractility,cardiacoutput,heartrate,and conductance.β, receptors :decrease theblood pressureSystolic blood pressure rise,diastolic pressure falls
A. Pharmacological effects 1.Cardiovascularsystem- β1 receptors : increases cardiac contractility, cardiac output, heart rate, and conductance. β2 receptors :decrease the blood pressure Systolic blood pressure rise, diastolic pressure falls. III. Receptor Agonists -Isoprenaline (Isoproterenol)
Isoproterenolcausesvasodilation,but stronglyincreasescardiacforceandrate.InfusionsoprotoreO(anuwed)Oean00888nae6HU)HignsseaO15mminttesTmeisoproterenoORLSRSSIignificantdecreaseaperiphorairesitanceIsoproterenoicausesmarkediydecreasedwithdiastolicpressure,increasedmoderateiysystolicpressure
2.Bronchial smoothmuusclebronchodilation3.Metabolism:increaseglycogenolysis,increased lipolysis.increases oxygen consumption
2.Bronchialsmooth musclebronchodilation 3.Metabolism: increase glycogenolysis, increased lipolysis, increases oxygen consumption
10.1TABLECardiovascularEffectsofCatecholaminesinHumans(intherapeuticdosesof0.1-0.4μg/kg/minlVor0.5-1.0mgsc)CardiovascularfunctionEpinephrineNorepinephrineIsoproterenolSystolicblood pressure0++++++Diastolic blood pressure++Mean blood pressure+0-++Total peripheralresistance++++Heart rate (chronotropic effect)++Stroke output (inotropic effect)+++++-0Cardiac output++++++Key:O=no cffect:+= increased:-=decreased.The number of symbols indicates the approximate magnitude of the responseTABLE10.2ResponseoftheMajorVascularBedstoUsualDosesoftheCatecholaminesVascular bedReceptortype*NorepinephrineEpinephrineIsoproterenolNoneCutaneous blood vesselsConstrictionConstrictionaNone (weak dilation)Visceral blood vesselsConstrictionConstrictionαRenal blood vesselsConstrictionConstrictionNone (weak dilation)aDilationDilationDilationCoronary bloodvesselsa,βDilationSkeletal muscleblood vesselsConstrictionDilationa, β2Pial blood vesselsDilationConstriction/dilationConstriction/dilationa,β$While virtually all blood vessels have a-receptors, some also have Q,-receptors Stimulation of either subtype generally results in vasocon-striction