(PM3B) Adrenergic Therapeutics Flashcards
What are the stages in catecholamine synthesis?
(1) Tyrosine converted to DOPA via tyrosine hydroxyls
(2) DOPA converted to dopamine via DOPA decarboxylase
(3) Dopamine converted to noradrenaline via dopamine ß-hydroxylase
(4) Noradrenaline converted to adrenaline via phenylethanolamine N-methyltransferase
What molecule provides negative feedback in catecholamine synthesis?
Noradrenaline
Where is noradrenaline released?
ALL post-ganglionic sympathetic fibres
Where is adrenaline released?
Adrenal gland
On which molecule does noradrenaline provide negative feedback on, in catecholamine synthesis?
Tyrosine hydroxylase
Where does noradrenaline bind?
Either alpha/beta adrenoceptors
What are the adrenoceptor subtypes?
(1) alpha-1
(2) alpha-2
(3) beta-1
(4) beta-2
(5) beta-3
What subtypes of alpha-1 adrenoceptor are there?
(1) alpha-1A
(2) alpha-1B
(3) alpha-1D
What subtypes of alpha-2 adrenoceptor are there?
(1) alpha-2A/D
(2) alpha-1B
(3) alpha-1C
Where are alpha-1 adrenoceptors located?
Smooth muscle
Where are alpha-2 adrenoceptors located?
(1) Smooth muscle
(2) Nerve terminals
Where are beta-1 adrenoceptors located?
Heart
Where are beta-2 adrenoceptors located?
(1) Smooth muscle
(2) Heart
(3) Skeletal muscle
(4) Nerve terminals
Where are beta-3 adrenoceptors located?
(1) Skeletal muscle
(2) Fat
What is the function of alpha-1 adrenoceptors?
(1) Vasoconstriction
(2) Contraction – relax GIT
(3) Glycogenolysis
What is the function of alpha-2 adrenoceptors?
(1) Contraction
(2) Inhibition of neurotransmitter release
What is the function of beta-1 adrenoceptors?
Increase cardiac rate + force
What is the function of beta-2 adrenoceptors?
(1) Vasodilation
(2) Bronchodilation
What is the function of beta-3 adrenoceptors?
(1) Thermogenesis
(2) Lipolysis
Which G protein does the alpha-1 adrenoceptor act on?
G-alpha-q
Which G protein does the alpha-2 adrenoceptor act on?
G-alpha-i/o
Which G protein does the beta-1 adrenoceptor act on?
G-alpha-s
Which G protein does the beta-2 adrenoceptor act on?
G-alpha-s
Which G protein does the beta-3 adrenoceptor act on?
G-alpha-s
What is the response of alpha-1 adrenoceptor binding?
Increased IP3
What is the response of alpha-2 adrenoceptor binding?
Decreased cAMP
What is the response of beta-1 adrenoceptor binding?
Increased cAMP
What is the response of beta-2 adrenoceptor binding?
Increased cAMP
What is the response of beta-3 adrenoceptor binding?
Increased cAMP
For which adrenoceptor subtype does noradrenaline have the greatest potency?
alpha-1