Adrenergic Agonsits Flashcards
Epi synthesis pathway
Tyrosine to DOPA to Dopamine to NE to Epi
B1 receptor
Gs alpha. leads to increased cAMP. Cholera toxin acts on this receptor in intestines and reverses pump. Is on the heart, stimulation by epi, NE, isoproterenol and B1 selective is dobutamine to cause increased HR and contractility. c
B2 receptor
Gs alpha increased cAMP. Is on the vasculature and bronchioles and stimulation by Epi (not NE), isoproterenol, and albuterol to lead to vasodilation and brochorelaxation
a1 receptor
Gq-> phospholipase C, smooth muscle contraction on the vasculature, and stimulated by epi, NE, phenylephrine to cause vasoconstriction.
a 2 receptor
G0 decreased cAMP. Is on nerve cell terminals and in the brain as a feedback mechanism. It is stimulated by epi, NE, and clonidine and leads to decreased NE release from body and less sympathetic activity.
Reserpine
inhibits the pump which puts NE into vesicles, leading to less NE available to be released into the synapse.
MAOI
Monoamine oxidase inhibitor- prevents NE breakdown leading to more effect of NE. Examples selegiline, procarbazine.
Tyramine
Reverses the direction of the axoplasmic catecholamine transporter and all free NE(not in vesicles) in the neuron will be pumped into the synapse.
Amphetamine
Reverses the direction of the axoplasmic catecholamine transporter and all free NE(not in vesicles) in the neuron will be pumped into the synapse.
Cocaine
inhibits the axoplasmic catecholamine transporter preventing reuptake of NE into the neuron.
Ephedrine
Reverses the direction of the axoplasmic catecholamine transporter and all free NE(not in vesicles) in the neuron will be pumped into the synapse.
Guanethidine
leads to degradation of NE stores by inducing release from the vesicle and degradation by MAOI, reducing sympathetic stimulation.
Pargyline
Monoamine oxidase inhibitor, can potentiate the action of catecholamines.
Dobutamine
B1 selective agonist contraindicated in a fib.
Phenylephrine
a1 selective agonist leading to smooth muscle contraction, and as an oral decongestant, prostate dilation/ relaxation
Doxazoin
AZOINs are a1 receptor antagonists.
Metaproterenol
B2 agonist, Leads to bronchodilation and vasodilation.
Terbutaline
B2 agonist, Leads to bronchodilation and vasodilation.
Albuterol
B2 agonist, Leads to bronchodilation and vasodilation.
Ritodrine
B2 agonist, Leads to bronchodilation and vasodilation.
Salmeterol
B2 agonist, Leads to bronchodilation and vasodilation.
Clonidine
a2 agonist, centrally acting, negative feedback loop for NE release
alpha-methyldopa
a2 agonist, centrally acting, negative feedback loop for NE release. Antihypertensive safe to use in pregnancy
Guanabenz
a2 agonist, centrally acting, negative feedback loop for NE release
Epinephrine
agonizes all sympathetic receptors. When a1 receptors are antagonized, see a drop in blood pressure more than normal because B2 receptors are agonized leading to vasodilation.
Terazosin
A1 antagonist leads to vasodilation.
Norepinephrine
Antagonizes a1 and B1 receptors, no effect on B2.
Isoproterenol
B1 and B2 agonists. would lead to vasodilation and tachycardia.
Dopamine
Positive ionotrope for B1, vasodilator in renal and mesenteric vasculature at lower conc, leads to vasoconstriction at higher doses.
Pseudoephedrine
stereoisomer of ephedrine. Release of NE via reversing the axoplasmic catecholamine transporter
guanadrel
leads to degradation of NE stores by inducing release from the vesicle and degradation by MAOI, reducing sympathetic stimulation.
Nicotine
Activates nicotinic receptor which leads to NE release from the post synaptic nerve in the sympathetics.
