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Adrenergic NS
Adreneergic Nervous System
Question | Answer |
---|---|
alpha 1 receptor location | post synaptically vascular + genitourinary, radial smooth muscle heart liver |
Alpha 1 receptor signaling | Gq, increase intracellular Ca2+ |
Alpha 1 receptor function | increase peripheral resistance, urinary retention, dilation of pupil increase force + excitability of heart stimulate gluconeogenesis + glycogenolysis |
Alpha 2 receptor location | pre synaptically: nerve terminalsPost synaptically: pancreatic Beta cells, vascular smooth muscles, platelets |
Alpha 2 receptor signaling | Gi/Go, decrease cAMP levels |
Alpha 2 receptor functions | inhibit release of NE (feedback inhibition)decrease insulin secretion, muscle contractionstimulate platelet aggregation |
Beta 1 receptor location | heart renal juxtaglomerular cells |
Beta 1 receptor signaling | Gs, increases cAMP levelsEpinephrine = norepinephrine |
Beta 1 receptor function | increased chronotropy, inotropy, AV node conduction velocity (rate, force, BP)increased renin secretion |
Beta 2 receptor location | smooth and skeletal muscle |
Beta 2 receptor signaling | Gs, increases cAMP levelsEpinephrine>Norepinephrine |
Beta 2 receptor function | smooth muscle relaxationglycogen catabolism in liver = increased plasma glucosestimulates glycogenolysis in skeletal muscles |
Beta 3 receptor location | adipose tissue |
Beta 3 receptor signaling | Gs, increases cAMP levels |
Beta 3 receptor function | lipolysis |
Physiological effects on blood vessels | a receptors=vasoconstrictionB receptors vasodilation |
Effects on heart | B1 positive inotropic + chronotropic effects |
effects on blood pressure | a receptors = increase baroreceptor reflex via AchB receptors = increase systolic, decrease diastolic via B2 |
effects on radial muscles | a receptors = mydriasis (pupil dilation) |
effects on intra ocular pressure | a receptors = incresae outflow of aqueous humorB receptors = increase aqueous humor production |
drugs used to treat glaucoma | a-agonistB-antagonist |
effects on bronchial muscles | B2 = bronchodilation |
effects on blood vessels of upper respiratory tract mucose | a receptors = vasoconstriction (nasal decongestant) |
effects on GI tract smooth muscle | a2 + B2 = relaxation (a2 more significant) |
effects on uterine smooth msucle | B2 = relaxation (delay labor) |
effecst on other smooth muscle | a receptors = urinary retention, ejaculation |
effects on adipose tissue | a2 receptors = inhibit lipolysisB3 = stimulate lipolysis |
effects on liver | B + a1 receptors = glycogenolysis (increase blood glucose) |
effects on pancreatic cells | a2 receptors = inhibit insulin releaseB receptors = stimulate insulin release |
effects on renal cells | a2 = inhibit renin releaseB1 = stimulate renin release |
epinephrine (sympathomimetic + catecholamine) | a + B agonist (all types) |
norepinephrine (sympathomimetic + catecholamine) | a1, a2, B1 agonist (not for asthma) |
dopamine (sympathomimetic + catecholamine) | B (moderate dose), & a (high dose) agonist |
isopretenrenol (sympathomimetic + catecholamine) | B1 & B2 agonist |
dobutamine (sympathomimetic + catecholamine) | B1 agonist, a1 effects at high doses |
phenylephrine (sympathomimetic + non-catecholamine) | a1 agonist |
oxymetazoline (sympathomimetic + non-catecholamine) | a1 & a2 agonist |
yohimbine & clonidine (sympathomimetic + non-catecholamine) | a2 agonist |
xsmoterol (sympathomimetic + non-catecholamine) | B1 agonist |
albuterol, terbutaline, ritodrine, salmetrol, formoterol (sympathomimetic + non-catecholamine) | B2 agonist |
Ephedrine uses (a1, B1, B2) | bronchospasm (emergency sub cutaneous)glaucoma (increases outflow of aqueous humor)anaphylactic shock (cadiac arrest)adjunct to local anesthetic ( increase duration of action, decrease toxicity) |
Norepinephrine uses (a1, B1) | shock (increases vascular resistance, increases BP)not really used anymore |
Isopreterenol uses (B1, B2) | stimulate hear tin emergency situationsNot really used anymore |
Dopamine uses (a, B) | shock (D1 receptor increase vascular resistance) |
Dobutamine uses (B1) | increase CO in CHF |
Phenylephrine uses (a1) | vasoconstriction via increase baroreceptor response, increase parasympathetic, decrease bradycardiamydriasisdecongestantSVT |
Methoxamine uses (a1) | vasoconstriction (increases BP)SVTovercome halothane induced HYPOtension |
Clonidine uses (a2) | HTN |
Albuterol, pibuterol, terbutaline uses (B2) | short acting bronchodilatior (acute asthma attack) |
Salmeterol, Formoterol uses (B2) | long acting bronchodilators, chronic asthma, before sleep |
Indirect acting sympathomimetics | amphetamine, cocaine, tyrmaine (MAOI) |
Mixed acting sympathomimetic | ephedrine |
Amphetamines | non catecholamine, inhibits MAOstimulates via DA --> NEincreased alertness, decreased fatigue, appetite and sleepincreases BP via a + B via NEADHD, narcolepsy, appetite control |
cocaine | indirect acting sympathomimeticblocks reuptake of catecholamines (increases DOA)CNS stimulant, euphoria via DA in limbic systemshorter acting than amphet. more intenselocal anesthetic (not used anymore) |
ephedrine | mixed acting sympathomimetic, non catecholaminereleases stored NE/catecholaminesdirectly stimulates a & B receptorsmild CNS stimulantincrease BP via a and B actionweak bronchodilatorasthma (prophylaxis, acute)nasal decongestant |