Autonomic Pharmacology DSA Flashcards
acetylcholine
NT of PS
NT for all preganglionic autonomics?
ACh to nicotonic receptors
postganglionic PS NT?
ACh on muscarinic
sympathetics to sweat gland NT
ACh to muscarinic
NT to somatic skeletal muscle?
ACh - to nicotinic
sympathetic NT to renal vascular smooth muscle
dopamine to D1 receptors
sympathetic to cardiac and smoth muscle, gland cells, and nerve terminals NT?
NE to alpha and beta receptors
norepinephrine
NT of sympathetics
catecholamine
epinephrine
synthesis in adrenal medulla
catecholamine
at adrenal medulla?
ACh binds nicotinic
-triggers release of 80% E, 20% NE
dopamine
precursor to NE and E
-synthesized in cytoplasm
acts on renal vascular smooth m**
synthesis of ACh
choline into neuron - depends on Na cotransport
ChAT - choline acetyltransferase
- combining acetyl CoA with choline
- to synaptic vesicle
release of ACh
AP triggers Ca influx
-Ca induces SNARE protein fusion with membrane - VAMP and SNAP
activation of nAChR
enhances ACh release
activation of mAChR
inhibits ACh release
acetylcholinesterase
breakdown of ACh - in synaptic cleft
-acetate and choline
nAChR location
all ganglia - PS and S
adrenal medulla - S
mAChR location
smooth and cardiac muscle
gland cells
nerve terminals
nAChR
ligand gated
-allow passage of Na
+ nicotine and ACh
mAChR
GPCRs
five subtypes
-
M2 and M3
mAChR subtype in smooth muscle
M2
mAChR subtype in cardiac muscle
catecholamines
NE, E, dopamine
major hormone of adrenal medulla
E
synthesis of catecholamines
tyrosine > dopa > dopamine > NE > E
VMAT-2
transports dopamine, NE, E, and serotonin across vesicle membrane
reserpine
inhibits VMAT-2
-leads to depletion of catecholamines from sympathetic nerve endings
responses to catecholamines
contraction glycogenolysis gluconeogenesis relaxation increased force and reate of cardiac muscle
termination of catecholamine signaling
- NET and DAT reuptake
- dilution
- metabolism - MAO and COMT
MAO
outer surface of mitochondria
COMT
cytoplasmic
-associated in liver
cotransmitters
in same vesicle
inhibit release of sympathetic NT?
M2 and M4 serotonin PGE2 histamine enkephaline DA alpha-2 receptors
enhance release of sympathetic NT?
beta-2 receptors
angiotensin II
nAChR
alpha 1 receptor activation
muscle contraction
- smooth muscle of vascular
- cardiac muscle
alpha 1 in gut?
activation leads to Ca
-hyperpolarization and muscle relaxation
alpha 2 receptor activation
vascular smooth m contraction
decreased insulin
decreased NE release
potency of agonists for alpha receptors
E > NE > isoproterenol
phenylephrine
activates alpha 1
clonidine
activates alpha 2
beta receptor mechanism
adenylyl cyclase
-incrased cAMP
beta 1 receptors
myocardium
- increased rate and force of heart contraction
- also increase AV nodal conduction velocity
beta 2 receptors
smooth muscle
-vascular bronchial, GU, GI smooth muscle relaxation
beta 3 receptors
adipose tissue
-lipolysis
decreased insulin secretion
alpha 2
-pancreatic islet beta cells
aggregation of platelets
alpha 2
decreased release of NE
alpha 2
increased renin secretion
beta 1
juxtaglomerular cells
dobutamine
activates beta 1
D1 receptors
renal smooth muscles
-dilation
dopamine activation
high concentration of dopamine
activate alpha-1 and beta-1
-increased heart rate and general vascular vasoconstriction
contraction of radial muscle of iris
alpha 1
mydriasis - dilation
contraction of sphincter muscle of iris
M3, M2
miosis - constriction
secretion of lacrimal gland
stronger M3,M2 activation
PS
increased heart rate and contractility
beta 1 > beta 2
decreased rate of heart rate and contractility
M2»_space; M3
blood vessels
no PS innervation
S to blood vessels
alpha 1, beta 2
vasoconstriction
endothelium
M3 - activates NO synthesis
tracheal and bronchial relaxation
beta-2
trachea and bronchial contraction
M2 = M3
decreased stomach motility, secretion and increased sphincter contraction of stomach
alpha 1 alpha 2 beta 1 beta 2
**intestines as well
increased stomach motilty and tone
increased sphincter relaxation
decreased secretion of stomach
M2 M3
**intestines as well
gallbladder relaxation
beta 2
gallbladder contraction
M
decreased renin from kidney
alpha 1
increased renin from kidney
beta 1
relaxation of bladder detrusor
beta 2
contraction of trigone and sphincter
alpha 1
contraction of detrusor
M3 > M2
relaxation of trigone and sphincter
M3 > M2
increased pregnant contraction of uterus
alpha 1
ejaculation
alpha 1
erection
M3
skin contraction and secretion
alpha 1
spleen contraction
alpha 1
spleen relaxation
beta 2
skeletal muscle contraction
beta 2
liver glycogenolysis and gluconeogenesis
alpha 1 and beta 2
pancreas beta cells insulin release
alpha 2
EDRF
short lived vasodilator for endothelium
-aka NO
like a PS response
-mAChR activation
stimuli for EDRF
ACh
products of inflammation
physical stimuli
release of EDRF
ACh activates mAChR
-NO produced by endothelial cells
NO causes relaxation
decreased blood pressure
sympathetic outflow
-renin release from kidney stimulated
elevated blood pressure
reduced sympathetic outflow
-reduced renin
increased parasympathetic outflow
baroreceptor reflex
variable monitored - MAP
-slow infusion of NE - increase peripheral vascular resistance
as a result, increased MAP - causes reflex of carotid sinus and aortic arch (baroreceptor) - which causes decreased sympathetic outflow and increased parasympathetic
phenylephrine
increased blood pressure
- raises MAP
- causes baroreceptor reflex in normal individual
histamine
decreased blood pressure
- decreased MAP
- increased sympathetic and decreased parasympathetic
