21: Autonomic Pharmacology Flashcards
Major nt of the parasymp system vs symp system
Parasymp: Ach
Symp: NE
Where is NE found?
Vast majority of post-ganglionic symp fibers
Where does Epi synthesis occur?
Adrenal medulla, few epi containing neuronal pathways in brainstem
Where in a neuron is dopamine synthesized?
Cytoplasm
Name some co-transmitters
ATP, neuropeptide Y, VIP, substance P
What enzyme forms ACh?
ChAT
What transports ACh into vesicles?
ATPase-dependent ACh vesicular transporter
Release of ACh into synaptic terminal
AP -> Ca enters cells -> Ca promotes. Fusion of vesicular membrane with cell membrane via SNARE proteins
What happens when ACh binds nAChRs
Binding -> Na entry -> depol and AP in post-ganglionic fiber
Main way ACh signaling is terminated?
ACHe (acetylcholinesterase)
Adrenergic neurotransmission
Neurotransmission of catecholamines (NE, Epi, DA)
End result of a1 receptor activation vs a2
A1: muscle contraction
A2: vascular SM contraction, decreased NE, decreased insulin
B1, B2, and B3 activation results
B1: cardiac increases
B2: SM relaxation
B3: lipolysis in adipose
Which DA receptor is relevant in this material and what does it cause?
D1 in renal SM -> vasodilation, natriuresis, diuresis
General rule for muscarinic receptor stimulation
Stimulates contraction of all SM
How does vascular relaxation occur if arteries are not innervated with parasymps?
MAChR activation via NO from endothelial cells
Other name for NO
EDRF; endothelium-derived relaxing factor
Where is ACh found? 3 locations
- All preganglionic Autonomics
- All post-ganglionic parasymps
- Few post-ganglionic symp fibers (sweat glands)
Cholinomimetic agents and two examples
Drugs that mimic Ach; AChR agonists, AChE inhibitors
Example of cholinoceptor-blocking drugs
AChR antagonists
Sympathomimetic agents
Drugs that mimic or enhance a- or B-receptor stimulation
