《藥理學(xué)》英文課件 Adrenergic agonists_第1頁
《藥理學(xué)》英文課件 Adrenergic agonists_第2頁
《藥理學(xué)》英文課件 Adrenergic agonists_第3頁
《藥理學(xué)》英文課件 Adrenergic agonists_第4頁
《藥理學(xué)》英文課件 Adrenergic agonists_第5頁
已閱讀5頁，還剩37頁未讀， 繼續(xù)免費(fèi)閱讀

下載本文檔

版權(quán)說明：本文檔由用戶提供并上傳，收益歸屬內(nèi)容提供方，若內(nèi)容存在侵權(quán)，請進(jìn)行舉報(bào)或認(rèn)領(lǐng)

文檔簡介

AdrenergicagonistsoverviewTheadrenergicdrugsaffectreceptorthatarestimulatedbynorepinephrineorepinephrineTheadrenergicneuronAdrenergicneuronsreleasenorepinephrineastheneurotransmitter.CNS,andbetweengangliaandtheeffectororgansinsympatheticnervoussystem.NeurotransmissionatadrenergicneuronsSynthesisofnorepiephrineStorageofnorepiephrineinvesiclesReleaseofnorepiephrine

BindingbyreceptorRemovalofnorepiephrinePotentialfatesofrecapturednorepiephrineAdrenergicreceptor

,wereinitiallyidentifiedonthebasisoftheirresponsestheadrenergicagonists,epinephrine,norepinephrine,isoproterenol

1receptorshaveahigheraffinityforphenylephrine.Thedrugclonidineselectivelybindsto2receptors

1receptors

thesereceptorsarepresentonthepostsynapticmembraneoftheeffectororgans.G-proteincoupling

2receptorsLocatedprimarilyonthepresynapticnerveendingsandonothercells.Thestimulationofthe

2receptorscausesfeedbackinhibitionoftheongoingreleaseofnorepinephrinefromthestimulatedadrenergicneuronreceptorCharacterizedbyastrongresponsetoisoproterenol.

1receptorand2receptorResultsinactivationofadenylyl

cyclaseandthereforeincreasedconcentrationofcAMPwithinthecellDistributionofreceptorsVasculaturetoskeletalmusclehaveboth1and2receptors,butthe2receptorspredominate.Theheartcontainspredominantly1receptorsDesensitizationofreceptorsProlongedexposuretothecatecholaminesreducestheresponsivityofthesereceptors.CharacteristicsofadrenergicagonistsDerivativesof-phenylethylamineCatecholamines:sympathomimeticaminesthatcontainthe3,4-dihydroxybenzenegroupNon-catecholamines:lackingthecatecholhydroxylgroupshavelongerhalf-lives.MechanismofactionofadrenergicagonistsDirect-actingagonistsindirect-actingagonistsMixed-actionagonistsDirect-actingadrenergicagonistsEpinephrineissynthesizedfromtyrosineintheadrenalmedullaandreleased.Interactswithbothandreceptors.Atlowdoses,effects(vasodilation)onthevascularsystempredominate,whereasathighdoses,effects(vasoconstriction)arestrongest.actionsCardiovascular:strengthenthecontractilityofthemyocardium(1effect)Respiratory:causespowerfulbronchodilation(2effect)Hyperglycemia:lipolysisTherapeuticusesBronchospasm:emergencytreatmentofanyconditionoftherespiratorytractwherethepresenceofbronchoconstrictionhasresultedindiminishedrespiratoryexchange.AcuteasthmaAnaphylacticshockTherapeuticusesGlaucoma:epinephrinesolutionreduceintraocularpressureinopen-angleglaucoma.Anaphylacticshock:forthetreatmentofTypeIhypersensitivityreactioninresponsetoallergensInanesthetics:increasethedurationofthelocalanesthesiaPharmacokineticsIntravenouslyforthemostrapidonsetofactionSubcutaneously,byendotrachealtube,byinhalation,ortopicallytotheeyeOraladministrationisineffectiveAdverseeffectsCNSdisturbance:anxiety,fear,tension,headache,andtremorHemorrhage:inducecerebralhemorrhageCardiacarrhythmias:norepinephrineCardiovascularactionsVasoconstrictionBaroreceptorreflexEffectofatropinepretreatment:TherapeuticusesIsusestotreatshockbecauseitincreasesvascularresistanceOtheractionsofnorepinephrinearenotconsideredclinicallysignificant.Itisneverusedforasthma.IsoproterenolIsoproterenolisadirect-actingsyntheticcatecholamine.Stimulatesbothbeta1andbeta2adrenergicreceptors.actionsCardiovascular:increaseheartrateandforceofcontraction,causeincreasedcardiacoutput.Beta2onarteriolesofskeletalmuscleresultinadecreasedperipheralresistanceMayincreasesystolicbloodpressureslightlypulmonaryAprofoundandrapidbronchodilationisproducedbythedrugOthereffects:otheractionsonbetareceptor,suchasincreasesinbloodsugarandincreasedlipolysisTherapeuticusesStimulateheartinemergencysituationsRarelyusedasbronchodilatorinasthmadopamineDopamine,theimmediatemetabolicprecursorofnorepinephrine

CanactivatealphaandbetaadrenergicreceptorsActionsCardiovascular:stimulatoryeffectonthebeta1receptorsoftheheart,havingbothinotropicandchronotropiceffects.Athighdoses,vasoconstrictionRenalandvisceral:dopaminedilatesrenalarteriolesbyactivatingdopaminergicreceptors,thusincreasesbloodflowtothekidneysandotherviscera TherapeuticusesShock:dopamineisthedrugofchoiceforshock.Itraisesthebloodpressurebystimulatingtheheart(beta1action).Dopamineisfarsuperiortonorepinephrine.AdrenergicantagonistsOverview:bindtoadrenoceptorsbutdonottriggertheusualreceptor-mediatedintracellulareffectsAlphaadrenergicblockingagentsReducesthesympathetictoneofthebloodvessels,resultingindecreasedperipheralvascularresistance.PhenoxybenzamineNon-selective,alpha1postsynapticandalpha2presynapticreceptorsLastabout24hafterasingleadministrationActionsCardiovasculareffects:thedecreasedperipheralresistanceprovokesareflextachycardiaEpinephrinereversal:reversethealphaagonistactionsofepinephrineTherapeuticusesIsusedinthetreatmentofpheochromocytoma,acatecholamine-secretingtumorofcellsderivedfromtheadrenalmedul

溫馨提示

  • 1. 本站所有資源如無特殊說明，都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請下載最新的WinRAR軟件解壓。
  • 2. 本站的文檔不包含任何第三方提供的附件圖紙等，如果需要附件，請聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
  • 3. 本站RAR壓縮包中若帶圖紙，網(wǎng)頁內(nèi)容里面會(huì)有圖紙預(yù)覽，若沒有圖紙預(yù)覽就沒有圖紙。
  • 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
  • 5. 人人文庫網(wǎng)僅提供信息存儲(chǔ)空間，僅對用戶上傳內(nèi)容的表現(xiàn)方式做保護(hù)處理，對用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯，并不能對任何下載內(nèi)容負(fù)責(zé)。
  • 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容，請與我們聯(lián)系，我們立即糾正。
  • 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時(shí)也不承擔(dān)用戶因使用這些下載資源對自己和他人造成任何形式的傷害或損失。

評論

0/150

提交評論