[ANS] Parasympathetic Drugs - Acetylcholine and Cholinoceptors

● Active uptake

● Formation of acetylcholine

[BIOSYNTHESIS OF ACETYLCHOLINE]

Biosynthesis of acetylcholine includes:

Active uptake of acetylcholine

[BIOSYNTHESIS OF ACETYLCHOLINE]

This is the first and RATE-LIMITING STEP in the synthesis of Ach.

presynapse

[BIOSYNTHESIS OF ACETYLCHOLINE]

In the active uptake of acetylcholine, choline enters in the _________.

choline transporter

[BIOSYNTHESIS OF ACETYLCHOLINE]

The entry of choline into the presynaptic neuron occurs via the transporter, known as:

Hemicholinium

[BIOSYNTHESIS OF ACETYLCHOLINE]

This drug is a CHOLINE TRANSPORTER INHIBITOR.

acetyl-CoA

[BIOSYNTHESIS OF ACETYLCHOLINE]

In the formation of acetylcholine, choline combines with _______ produced in the mitochondria.

mitochondria

[BIOSYNTHESIS OF ACETYLCHOLINE]

In the formation of acetylcholine, choline combines with acetyl-CoA produced in the ______.

Choline acetyltransferase (ChAT)

[BIOSYNTHESIS OF ACETYLCHOLINE]

Catalyzing enzyme in the formation of acetylcholine.

Vesicle-associated transporter (VAT)

[STORAGE OF ACETYLCHOLINE]

Acetylcholine enter the vesicles through _______.

Vesamicol

[STORAGE OF ACETYLCHOLINE]

This drug is a vesicle-associated transporter (VAT) inhibitor.

Alpha latrotoxin

[RELEASE OF ACETYLCHOLINE]

This drug is an acetylcholine exocytosis release ENHANCER.

Botulinum toxin

[RELEASE OF ACETYLCHOLINE]

This drug is an acetylcholine exocytosis release INHIBITOR.

Acetylcholinesterase (hydrolase)

[TERMINATION OF ACETYLCHOLINE]

Acetylcholine is metabolized by:

anticholinesterase

[TERMINATION OF ACETYLCHOLINE]

Acetylcholinesterase (hydrolase) hydrolyzes ACh to choline and acetate which is inhibited by:

Passive diffusion

[TERMINATION OF ACETYLCHOLINE]

Acetylcholine move through synapses via:

TRUE

[TERMINATION OF ACETYLCHOLINE]

TRUE OR FALSE:

Acetylcholine DOES NOT undergo REUPTAKE.

Metyrosine

[DRUGS ACTING ON SYMPATHETIC]

This drug inhibits BIOSYNTHESIS of CATECHOLAMINES.

Reserpine

[DRUGS ACTING ON SYMPATHETIC]

This drug inhibits STORAGE of CATECHOLAMINES.

● Tyramine

● Ephedrine

● Amphetamine

● Angiotensin II

● Methamphetamine

[DRUGS ACTING ON SYMPATHETIC]

These drugs ENHANCE the RELEASE of CATECHOLAMINES.

● Guanethidine

● Guanadrel

● Bretylium

[DRUGS ACTING ON SYMPATHETIC]

These drugs INHIBIT the RELEASE of CATECHOLAMINES.

● Cocaine

● Atomoxetine (SNRIs)

● Sibutramine (SNRIs)

● TCAs

[DRUGS ACTING ON SYMPATHETIC]

These drugs INHIBIT the REUPTAKE of CATECHOLAMINES.

MAO inhibitors

● Moclobemide - selective MAO-A inhibitor (reversible)

● Phenelzine - non-selective MAO-A and MAO-B inhibitor (irreversible)

● Isocarboxazid - non-selective MAO-A and MAO-B inhibitor (irreversible)

● Tranylcypromine - non-selective MAO-A and MAO-B inhibitor (irreversible)

● Selegiline - selective MAO-B inhibitor (irreversible at low doses; inhibits MAO-A at high doses)

COMT inhibitors

-capones

● Entacapone

● Tolcapone

[DRUGS ACTING ON SYMPATHETIC]

These drugs INHIBIT the MAO and COMT.

Hemicholinium

[DRUGS ACTING ON PARASYMPATHETIC]

This drug INHIBITS the BIOSYNTHESIS of acetylcholine.

Vesamicol

[DRUGS ACTING ON PARASYMPATHETIC]

This drug INHIBITS the STORAGE of acetylcholine.

Alpha latrotoxin

[DRUGS ACTING ON PARASYMPATHETIC]

This drug ENHANCES the RELEASE of acetylcholine.

Botulinum toxin

[DRUGS ACTING ON PARASYMPATHETIC]

This drug INHIBITS the RELEASE of acetylcholine.

Acetylcholinesterase inhibitors

[DRUGS ACTING ON PARASYMPATHETIC]

These drugs inhibit the metabolism of acetylcholine.

● Muscarinic-1 (M1)

● Muscarinic-2 (M2)

● Muscarinic-3 (M3)

● Nicotinic N

● Nicotinic M

[CHOLINOCEPTORS]

Cholinoceptors include:

Type II (GPCR)

[CHOLINOCEPTORS]

Muscarinic and nicotinic receptors belong to what type?

M1

[CHOLINOCEPTORS]

This muscarinic receptor is found in the PARIETAL cells. This activates the PROTON PUMP, resulting in HCl production.

M2

[CHOLINOCEPTORS]

This muscarinic receptor is found in the ATRIAL of the HEART, causing BRADYCARDIA.

M3

[CHOLINOCEPTORS]

This muscarinic receptor is found in EXOCRINE glands, causing WETNESS (salivation, lacrimation, sweating).

M3

[CHOLINOCEPTORS]

This muscarinic receptor is found in SMOOTH MUSCLES (CONTRACTION):

● Eyes

- ciliary = near vision

- circular muscles (in pupils) = miosis

● Bronchi = bronchoconstriction

● GIT = bowel movement

● Urinary bladder = urination

Nicotinic N

[CHOLINOCEPTORS]

This nicotinic receptor is found in GANGLIONS, responsible in SYNAPTIC NEUROTRANSMISSION.

Nicotinic M

[CHOLINOCEPTORS]

This nicotinic receptor is found in NEUROMUSCULAR END PLATES, responsible in SKELETAL MUSCLE CONTRACTION.