Konorev Adrenergic Drugs Flashcards
adrenergic receptors can be divided what 2 was?
genetic analysis/separation and pharmacologically
alpha 1 receptor is associated with what kind of G protein?
Gq
what kind of G protein with alpha 2?
Gi
Gq activates what?
IP3 and MAPK pathways
terminally differentiated cells that have Gq stimulation results in what?
hypertrophy
beta receptors activate what?
AC
activation of which adrenergic receptor will increase levels of cAMP in tissue?
Beta1
which adrenergic receptor is found on most vascular smooth m.?
alpha1
activation of which adrenergic receptor will decrease levels of cAMP in target tissues?
D2 (dopamine 2)
how to indirect acting drugs change neurotransmission?
change level of concentration of norepinephrine (or dopamine) at target receptors
phenylephrine is mostly selective for what receptor?
alpha1
we need to know what to know the pharmacodynamics of an adrenergic drug?
where receptors are located and effects of receptor activation
what is tachyphylaxis?
accute (sudden) decrease in the response to a drug after its administration
epinephrine has what effect on cardiac function?
increase force of contraction (positive ionotropic effect), HR, increase conduction velocity at AV node, Beta 1 receptors
epinephrines effects on vascular tone varies because?
there are different types of receptors found in vascular beds:
skin/mucous membranes: alpha1
skeletal m.: alpha1 and beta2
renal, cerebral: D1 and alpha1
epinephrine effect on respiratory system?
relax bronchial m. (beta 2), decrease bronchial secretion and congestion within mucosa (alpha 1)
what does epinephrine cause in skeletal m.?
causes m. tremor (beta 2) — side effect!!
increases K+ uptake (beta 2)
increase in K+ uptake by skeletal m. can cause what systemically?
hypokalemia and decrease K excretion by kidneys
what does epinephrine do to fat cells?
increase free fatty levels in blood (Beta) due to increase lipolysis
how does epinephrine elevate blood sugar?
enhances liver glycogenolysis (beta 2) and
inhibits insulin release (alpha 2 and beta 2)
– decreases skeletal m. use of glucose as well.
norepinephrine lacks agonist effects on what kind of receptors?
beta 2
NE does what to heart?
cardiac stimulant but reduces HR—> bradycardia
norepinephrine has what efffect on vessels? why?
potent vasoconstrictor, does not have opposing Beta 2 vasodilation to offset (unlike epinephrine)
what is blood pressure equal to?
BP= COx vascular resistance
what does norepinephrine do to BP?
largely increase
dopamine1 stimulation causes what?
vasodilation
where are there high density D1 receptors?
renal, cerebral, mesenteric and coronary vessels
activation of D2 receptor does what?
suppresses NE release
at higher does dopamine causes what on heart?
activates B1 in heart
even higher doses of dopamine cause what?
vascular (alpha1) AR–> vasoconstriction
which acts primarily on receptors located on membrane of autonomic effector cell?
norepinephrine
has to be direct acting drug
dilation of vessels in skeletal m., constriction of cutaneous vessels, and direct positive ionotropic and chronotropic effects on the heart are all actions of…?
epinephrine
phenylephrine is what kind of drug?
alpha 1 agonist
what effect does phenylephrine have on vessels?
increase in vasoconstriction and BP elevation
phenylephrine causes activation of what reflex?
baroreflex
clonidine activates what kinds of receptors?
alpha 2
what does cloidine do in lower brainstem?
decreases sympathetic outflow, reduces BP, bradycardia
local application of clonidine causes?
vasoconstriction
where does clonidine act?
alpha 2 receptors pre-synaptically, decreases NE release
– NE feedback on self (to alpha 2 receptor)
what does clonidine do to NE levels with cardiovasular system?
decreases:
alpha1- arterial smooth m.– vasodilation
beta 1- heart– decreases HR and CO
isoproterenol is what kind of agonist?
non-selective beta agonist
what isoproterenol do in heart?
increase ionotropic and chronotropic action, increase CO
main difference in isoproterenol and epinephrine?
isoproterenol does not activate alpha 1 receptors
what is the result of alpha 1 activation with isoproterenol?
increase in systolic but drop in diastolic, mean arterial pressure drops too
drop in blood pressure causes activation of what?
baroreflex— leads to significant tachycardia
dobutamine activates?
selective beta 1 (also found to have alpha 1 receptor activity, racemic mix that activates and antagonizes alpha 1)
the alpha 1 activity of dobutamine causes what effect compared to isoproterenol?
less prominent chronotropic action
what are the names for the beta2 selective agonists?
terbutaline, albuterol
what can beta 2 agonists cause?
bronchodilation and relaxation of uterus
phenyephrine causes what?
constriction of vessels in the nasal mucosa
Adrenergic modulate what?
adrenergic transmission and control the function of sympathetic nervous system
