BetaBlockersAbsorptionβ-受体阻断剂的吸收

《BetaBlockersAbsorptionβ-受体阻断剂的吸收》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、BetaBlockersCourse:PHM142Term:Fall2012GroupMembers:GaryLam,MatthewPak,andKangHaiChenPHM142Fall2012Instructor:Dr.JeffreyHendersonDiscoveryDiscoveredbyJamesWBlackin1962PropanololandPronethalolarethefirstclinicallysignificantbetablockersUsedforanginapectoris

2、-chestpainfromrestrictedbloodflowtoheartWhatarebetablockersNormally,catecholaminesbindbetareceptorsBetareceptors–GproteincoupledreceptorBindsepinephrineandnorepinephrineStimulatethesympatheticnervoussystemFightorflightresponse(wideningpupils,mobilizingene

3、rgy,anddirectbloodfromnon-essentialorganstoskeletalmuscles)BetablockersareBetaAdrenergicblockingdrugsThesedrugsbindtobetareceptors(akaadrenergicreceptors)WhyBetaBlockersAcuteandchronicstimulationofreceptorsindiseasestates(e.g.Ventriculardysfunction)canlea

4、dtodesensitizationBetablockerscounterexcessivesignallingbycompetitiveinhibitionAllowforre-sensitizationofreceptorsBetaBlockersAbsorptionBetablockersenterthebloodstreamthroughtheGItract.BetaBlockerMechanismofActionBetaBlockerMechanismofActionCompetitiveinh

5、ibitorsCompetewithcatecholaminesforbetareceptorBetablockerbindingdecreasesbindingsiteavailabilityforcatecholaminesBlockingcatecholaminebindingsiteweakenstheeffectofstresshormonesReduceheartrate,reducebloodpressure,etcBetaReceptorsBeta1AdrenergicReceptorF

6、oundinHeart,Eyes,andKidneysIncreasecardiacoutput(heartrate,strokevolume,etc)Increasereninsecretionfromkidneys(bloodpressureregulation)Increaseghrelinsecretionfromstomach(hungersignals)Beta2AdrenergicReceptorFoundinlungs,liver,uterus,vascularsmoothmuscles,

7、gastrointenstinaltract,andskeletalmuscleRelaxsmoothmusclesLipolysisofadipocytesAnabolismsofskeletalmuscleEtcBeta3AdrenergicReceptorFoundinfatcellsLipolysisofadipocytesBetaReceptorStructure7TMHelixReceptorsGproteincoupledTypes:Beta1:heart&brainBeta2:heart,

8、lungs,tissueEpinephrine/NorepinephrineSignallingPathwayEpinephrine/NorepinephrineSignallingPathwaySymNScatecholaminereleaseInactiveGproteinisGDPboundLigandbindingchangesconformationofreceptorGDPandbeta-gammasubunit