Pharmacology Flashcards
exceptions to SNS PSNS NT rules
1) SNS activates sweat glands with ACh via mAChR—>Sweat
2) SNS activates adrenal medulla with ACh via nAChR—>EPI/NE release
Renal smooth muscle responds to DA release from SNS
nAChR
ionotropic (ligand gated ion channels0
in the brain and adrenal medulla
excitation
agonists: ACh, Nicotine
mAChR
metabotropic (GPCR)
PSNS: CNS, autonomic ganglia, effector organs: cardiac, smooth muscles, glands, nerve terminals), and sweat glands (SNS)
Excitatory or inhibitory, agonized by ACh and muscarine
M2 receptors
PSNS receptor on the heart
Inhibits cAMP—>inc K conductance—>
decrease HR
M3 receptor
PSNS receptor found on glands, smooth muscle, endothelium
IP3/DAG—>muscle contraction in lung smooth muscles
Tyr—>DOPA–>DA
within the nerve cytoplasm
DA—>NE—>EPi
occurs within the vesciles of teh neurons
VMAT-2
shuttles in NTs into vesicles
-promiscuous (NE, Ei, DA, 5HT)
release upon after Ca2+ influx
if this is blocked by RESERPINE—>decreased SNS tone–>decrease BP
NET and DAT
NE and DA transporters that bring these NTs back into neuron where they can be recycled by MAO and COMT
A1 adrenergic receptors
found postsynaptically in smooth muscle
Epi> NE
cause contraction of ALL smooth muscle
ex: vasoconstriction
blocked pharmacologically for HT
NO PSNS ON VASCULATURE
B2 adrenergic receptors
found mostly in smooth muscle
EPI»NE
think epi pin
Cause smooth muscle relaxation
ex: vasodilation (lungs)
B1
found in cardiac muscle
Epi=NE
A2
found mostly pre junctional
Epi>NE
Muscarinic receptors on the heart
contract smooth muscles
Innervation of the vasculature
A1—>vasoconstriction (SNS)
NO PSNS receptors….but muscarinic agonists give IV cause VD due to activation or endothelial release of NO
*think nitroglycerine (causes relaxation of cardiac vessels by this mechanism-do not give exo ACh)
