2.2 - CNS Drugs (General) Flashcards
Which two substances are combined by ChAT to produce ACh?
Choline + Acetyl CoA
What is ChAT?
Choline Acetyl Transferase
–> The enzyme that converts choline and acetyl CoA to produce ACh.
Which enzyme breaks down ACh within the synaptic cleft?
Acetylcholine esterase (AChE)
AChE turns ACh into…
Choline (which is taken back up and made into more ACh), and acetate (Which enters the Krebs cycle)
Which drug results in the inhibition of choline reuptake from synapse?
Hemicholinium
–> Decreased further synthesis of ACh
What is hemicholinium?
A drug that inhibits choline reuptake within the synapse
Which drugs inhibits ACh storage in the vesicle?
Vesamicol
What does vesamicol do?
Inhibits ACh storage in vesicle.
Which drug prevents ACh release?
Botulinum toxin
What does the botulinum toxin do to the body?
Prevent ACh NT release, resulting in muscle paralysis.
What drug displaces ACh from vesicles?
Latrotoxin - black widow venom
What does black widow toxin do to the body?
Latrotoxin displaces ACh from vesicles, therefore preventing its release. Leading to muscle paralysis.
What are the two kinds of cholinergic receptors?
Muscarinic and nicotinic
Give an example of a PSNS cholinergic receptor agonist.
Muscarine
Give an example of a PSNS cholinergic receptor antagonist.
Atropine
What does muscarine do to the body?
Muscarinic cholinergic receptor agonist
What does atropine do to the body?
Muscarinic receptor antagonist
Which drug inhibits AChE?
Neostigmine, and nerve gases
What is neostigmine?
AChE inhibitor - increases ACh levels by preventing is breakdown.
All postganglionic receptors (of the neuron itself) in the ANS have which kind of ACh receptor?
Nicotinic
Where are muscarinic receptors found in target tissue?
Smooth muscle and glands, sweat glands.
All target tissue of the PSNS has which kind of cholinergic receptor?
Muscarinic (Smooth muscle and glands all have muscarinic ACh receptors)
Where are nicotinic receptors found in the body?
On postganglionic neurons, skeletal muscle, and the adrenal medulla
Where do SNS target tissues have muscarinic receptors?
In sweat glands
What is a general rule for the roles of a1 receptors?
They are involves in vasoconstriction, or constriction
What is the general rule for a2 receptors?
They are involved in negative feedback
What is the general rule for B1 receptors?
The heart and kidneys
What is the general rule for B2 receptors?
Relaxation/dilation
Which two structures have B3 adrenergic receptors? What do they signal for?
Adipose tissue - lipolysis
Bladder (detrusor) - Relaxation
What kind of adrenergic receptors promote glycogenolysis and gluconeogenesis in the liver?
B2
What kind of adrenergic receptors signal for decreased GI motility? What about GI secretions?
–> B2 for motility
–> a2 for secretions
What kind of adrenergic receptors signal for increased insulin secretion from the pancreas? What about decreased insulin secretion?
–> Increased is B2
–> Decreased is A2
What kind of adrenergic receptors trigger for relaxation of the bronchi, uterus and bladder, as well as vasodilation near skeletal muscles and coronaries?
B2
What kind of adrenergic receptors signal for increased heart rate and increased force of contraction?
B1
What kind of adrenergic receptor signals for renin release on the kidneys?
B1
What kind of adrenergic receptor signals for inhibition of NA release on presynaptic neurons?
a2
What kind of adrenergic receptor signals for mydriasis, piloerector muscles, ejaculation, internal urinary sphincter contraction, and vasocontraction near the skin and splanchnic vessels?
a1
What kind of adrenergic receptor signals for thick viscous secretions from the salivary glands?
A1
Where are nicotinic neuronal receptors found? What does it do?
–> ANS postganglionic ganglions (complex and difficult to predict)
–> Adrenal medulla (NE and E release at a 4:1 ratio)
Where are nicotinic muscular receptors found?
Somatic skeletal muscles only. Leads to depolarization and contraction
Which kind of cholinergic receptors are found in the brain?
M1, M4, M5.
Where are M2 receptors found?
In the heart muscle - decreased heart rate, decreased force of atrial contraction
Where are M3 receptors found? what do they do?
Smooth muscle and glands (Salivary, lacrimal, bronchial GI)
Stimulates iris sphincter for miosis
Contraction of ciliary muscle (accommodation)
Sweat glands - diaphoresis (sympathetic)
Which part of the SNS used cholinergic receptors? Which one does it use?
Sweat glands - M3
