Adrenergic Receptors

cuvasine's version from 2015-10-07 00:47


Question Answer
Where is alpha 1 receptor located?Post-synaptic
What effect does alpha 1 receptor cause on smooth muscles, and motility and tone of GI?Relaxation/inhibition
Alpha 1 receptor skin, mucosa, renalvasoconstriction
alpha receptor urinary or GIT sphinctorcloses them
alpha 1 receptor vas deferens?contraction causing ejaculation
alpha 1 receptor on spleenic capsul?contraction leading to release of RBCS into circulation
alpha 1 receptor on eye?contraction of radial muscle which leads to pupil dilation
Alpha 1 receptor- misc. effectsPiloerection (goosebumps) and glycogenolysis
Alpha 1 receptor is coupled with what?Gq mediates phospholipase C--> IP3 and DAG
what does Ip3 cause?releases Ca
what does DAG cause?PKC
Order of potency of isoproterionol/ epi/ NorEpiEpi > Norepi> Isoproterenol
Where are alpha 2 receptors found?presynaptic nerve endings (predominant) Post synaptic beta cells of pancreas and BV's
Alpha 2 receptors are coupled with what G protein?Gi (inhibitory) binds adenylcyclase- needs ATP for cAMP (2nd messenger) for smooth muscle contraction; also released Ca for inhibition of transmitter release
What receptors relax/inhibit GIT tone and motility?A1, A2, B2
B2 receptors coupled with..?Gs causing rapid conversion from ATP to cAMP
B2 receptors found?All smooth muscles, BV of skeletal muscles
B2 has affinity for?Epinephrine
B2 effect on bronchial muscle; motility and tone of GIT, and detrusor muscle of bladder?Relaxation/inhibitory effect
B2 effect on splanchnic, coronary, and skeletal muscle BV?vasodilation
B2 effect on ciliary muscles?relaxation
B2 miscellaneous effects?Glycogenolysis, increased secretion of insulin from B cells pancreas
What receptors act on the uterus?A1, A2, B2
Receptors on the uterus...?Variable depending on life phase, overall relaxation in gravid period contraction during parturition
What occurs to cardiovascular system when theres a rise in NE(B1 receptor) increase in BP; compensated by increase in ACH (bagel tone) reducing HR- homeostasis mech
Agonist does..?affinity and efficacy
IndirectIncreases/fabors release of NT into synaptic junction
DirectBinds directy to adrenergic receptor
AntagonistBinds and prevents binding of endogenous mediators; Only affinity does not illicit a response
B1 receptor details-Gs-->rapid conversion from ATP to cAMP -heart, juxtaglomerular apparatus of kidney, fat cells
B1 affinity?NE and Epi equally
B1 found?heart muscle
B1 causes?increase HR, Increase BP, Improves cardiac contraction increasing cardiac output. +++ inotropic effect, lipolysis