Cholinergic Agonists and Antagonists (Kruse) Flashcards
Review:
What are the parasympathetic NTMs?
What are the parasympathetic receptors?
NTMs: Ach
Receptors: nAChR, mAchR
Review
What are the sympathetic NTMs>
What are the sympathetic receptors?
NTMs: Ne>Epi (DA); Ach
Receptors: a, B (D), nAchR, mAchR
What are the four events at the cholinergic nerve terminal?
- Ach synthesis
- Ach storage
- Ach release
- Ach destruction
What are the four events at the adrenergic nerve terminal?
- synthesis
- storage
- release
- reuptake
M1 receptors
Location:
Structure:
Mechanism:
Nerves
GPCR, Gq11
IP3, DAG cascade
M2
Location:
Structure:
Mechanism:
heart, nerves, Sm. muscle
GPCR, Gi/o
inhibits cAMP production, activates K channels
M3
Location:
Structure:
Mechanism:
Glands, Sm. muscle, endothelium
GPCR, Gq/11
IP3, DAG
M4
Location
Structure
Mechanism
CNS
GPCR, Gi/o
Inhibits cAMP production
M5
Location
Structure
Mechanism
CNS
GPCR/Gq11
IP3, DAG
Nn
Location
Structure
Mechanism
postganglionic cell body, dendrites, CNS
a and B only
Na, K depolarizing ion channel
In most organs, which receptor type is predominant?
Which receptor type predominates in the heart?
What are the most common receptor types in smooth muscle?
M3
M2
M3 and M2
What is the function of cholinergic agonists?
mimic the actions of Ach on nAchRs and mAchRs
classified based on MOA (direct or indirect)
what are the direct acting cholinergic agonists?
Acetylcholine
Methacholine
Carbachol
Bethanechol
metabolized by AchE
Does Ach display muscarinic or nicotinic action?
Does Methacholine display muscarinic or nicotinic actions?
Does Carbachol display muscarinic or nicotinic actions?
Does Bethanechol display muscarinic or nicotinic actions?
Both equally
Muscarinic only
both, but more nicotinic
Muscarinic only
Which direct cholinergic agonists are uncharged and highly absorbed
muscarine and pilocarpine (chiefly muscarinic acting)
nicotine and lobeline (chiefly nicotinic acting)
Which direct acting cholinergic agonists are charged and poorly absorbed?
Ach
Methacholine
Carbachol
Bethanechol
Indirect cholinergic agonists are also known as?
These come in three flavors. What are they?
AChE Inhibitors
Alcohols (reversible)
Carbamic Acid Esters (reversible, long lasting)
Organophosphates (irreversible, covalent)
Which AchE inhibitors are charged and poorly absorbed?
Neostigmine
Carbaryl
Physostigmine
Edophonium
Which AchE inhibitors are uncharged and highly absorbed?
Echothiophate
Soman
Parathion
Paraoxon
Malathion
Malaoxon
What are some general parasympathetic effects of cholinergic agonists?
Miosis
decreased HR, contraction and conduction velocity
vasodilation in low dose, vasoconstriction in high dose
bronchoconstriction and increased secretions
increased GI motility with sphincter relaxation and increased secretions
contracts detrusor in bladder and relaxes trigone and sphincter
sweat secretions
What are the major uses of direct acting cholinergic agonists?
glaucoma and accomodative esotropia (crossed-eyes)
post-op ileus
congenital megacolon
urinary retention
GERD
xerostomia/Sjogren’s
What are the symptoms of toxicity with direct acting muscarinic stimulants?
N/V/D, urinary urgency
salivation/sweating
vasodilation
bronchoconstirction
SLUDGE (increased gland secretions)