Introduction To Autonomic Pharmacology Flashcards
What is the major neuroxmitter of the SNS
NE
Where is Epi usually found and where is it made
Found in general circulation, made in adrenal medulla from AcH to nAChR on chroffamin cells
What is the precursor to NE and Epi and where is it synthesized
Dopamine (DA) which is synthesized in the cytoplasm of neurons
What is the role of choline transporter
Transports choline from the extracellular space into neurons for use as precursor of ACh
What enzyme catalyzes the synthesis of ACh? And what does it combine
Choline acetyltransferase (ChAT) by cmobinging acetyl co A with choline
What stores ACh
ATPase dependent ACh vesicular transporter which puts ACh into vesicles
What protein complex is responsible for the binding of the vesicle to the presynaptic membrane
SNARE
What pre-synaptic membrane interacts with the vesicle via snare to open into the synaptic cleft
VAMPS and SNAPS
What destroys ACh in the synaptic cleft
acetylcholinesterase (AChE)
What signaling methods do muscarinic receptors use
GPCRs
Where are M2 receptors located and what do they do
Heart, nerves, SM
Through Gi, they inhibit AC which causes a decrease in cAMP and in activation of K channels which will slow HR and effect phase 0 of SA AP as well as faster repol. For myocytes
Where are MS receptors located and what do they activate
Located in SM and the endothelium
Activate PLC, IP3, and DAG which causes an increase in Ca
Nicotinic Receptors are what type of channels
Ligand gated channels
DA is the predominant transmitter of what
The mammalian extrapyramidal system
What transports DA, Ne, and Epi into the vesicle during de novo synethesis
VMAT - 2
Inhibiting VMAT - 2 will do what
Inhibit amount of catecholamines from synthetic nerve endings
The conversion of tyrosine to DOPA and DOPA to DA occurs where
In the nerve cytoplasm
What two proteins reuptake NE and DA from the synaptic cleft
NET and DAT
What do a1 receptors do
What about a2?
Muscle contraction (a1)
Vascular SM contraction, decreased insulin secretion, and decreases NE
What do B1 receptors do and where are they found
Found in the myocardium
Increased inotropy and chronotropy and AV nodal conduction dromotropy
What do B2 receptors do when activated and where are they found
Found on other smooth muscle besides the vasculature
Causes bronchial and gastrointestinal SM relaxation
All beta receptors use what type of signaling which causes what
Gs which increases AC and cAMP
DA receptors are what type of receptors
GPCRs
What does D1 activate
Increases cAMP and causes vasodilation, and diuresis via renal smooth muscle
In general, what does a1 and B2 do to smooth muscle
A1 - vasoconstriction
B2 - relaxation
Which mAChR is found mostly in the heart
M2
Is the smooth muscle of blood vessels innervated by PSNS
NO
What does vascular relaxation occur from
ACh and mAChR activation via release of NO
What two enzymes break down catecholamines in the synaptic cleft
Monoamine oxidase (MAO) Catechol - O - methyltransferase (COMT)
Parasympathetic activity in the M3 receptors of the endothelium activate what
NO which causes vasodilation
What happens in CHF
Decreased decreased baroreceptor firing which causes an increased SNS and thus an increased HR and contraction and preload and water retention which makes the problem worse
