Autonomic drugs

Question 1

ACH formation/storage/releasing and back in neuron - process

Answer 1

choline passes through membrane –> choline + acetyl - coa –> ACH (enzyme ChAT) –> ach in the vesicle –> Exocytosis (helped by Ca2+) –> break down into choline + acetate (via acetylcholinesterase) –> choline back into neuron

Question 2

acetylcholinesterase break down Ach into

Answer 2

choline + acetate

Question 3

ACH formation/storage/releasing and back in neuron - inhibitors of the process

Answer 3

Hemicholinium - blocks choline reabsorption
Vesamicol –> blocks Ach storage in vesicle
Botulinum –> blocks exocytosis
AChE –> blocks acetylcholinesterase

Question 4

ion that promote exocytosis

Answer 4

Ca2+

Question 5

Vesamicol action

Answer 5

blocks Ach storage in vesicle in cholinergic neuron

Question 6

Hemicholinium action

Answer 6

blocks choline reabsorption in cholinergic neuron

Question 7

Norepinephrine formation/storage/releasing and back in neuron - process

Answer 7

absorption of Tryosine by neuron –> tyrosine becomes DOPA –> dopamine –> dopamine in vesicle –> dopamine in vesicle becomes Norepinephrine –> exocytosis (helped by Ca2+) –>norepinphrin in the cleft –> a. receptor b. negative feedback (α2) c. reuptake d. diffusion, metabolism

Question 8

receptors that influence exocytosis of norepinephrine in noradrenergic neurons

Answer 8

AT II –> +

α2 –> -

Question 9

Norepinephrine formation/storage/releasing and back in neuron - inhibitors of the process

Answer 9

1. Metyrosine –> block the formation of DOPA from tyrosine
2. Reserpine –> blocks the entrance of Dopamine into the vesicle
3. Bretylium –> blocks exocytosis
4. guanethidine –> blocks exocytosis
5. Cocaine –> blocks reuptake
6. TCAs –> blocks reuptake
7. amphetamine –> blocks reuptake

Question 10

Norepinephrine formation/storage/releasing and back in neuron - drugs that facilitates this process

Answer 10

amphetamine + ephedrine –> promote exocytosis

Question 11

norepinephrine - exocytosis inhibitors and promoters

Answer 11

inhibitors –> Bretylium, guanethidine

promoters –> amphetamine, ephedrine

Question 12

blockers of norepinephrine reuptake

Answer 12

1. Cocaine
2. TCAs
3. amphetamine

Question 13

blockers of norepinephrine formation

Answer 13

metyrosine –> blocks tyrosine to DOPA

Reserpine –> blocks entrance of dopamine to vesicle

Question 14

Amphetamine - the whole mechanism of action

Answer 14

use the NE trasnporter (NET) to enter the presynaptic terminal, where it utilizes the vesicular monoamine transporter (VMAT) to enter vesicles –> this displaces NE from the vesicles –> once NE reaches a concentration threshold within the presynaptic terminal, the action of NET is reversed, and NE is expelled into the cleft

Question 15

Tyramine metabolism

Answer 15

normally degraded by Monaoamine oxidase (MAO)

Question 16

Tyramine levels are increased in

Answer 16

in patients taking MAO inhibitors (that normally degrade tyramine) who ingest tyramine-rich foods (eg. cheese, wine)

Question 17

tyramine reach foods

Answer 17

1. cheese

2. wine

Question 18

excess tyramine - mechanism of action

Answer 18

enters presynaptic vesicels and displaces other nuerotramsitters (eg. NE) –> increases active presynaptic neurotransmitters –> increases diffusion of neurotransmitters into synaptic cleft
–> hypertensive crisis

Question 19

excess tyramine - presentation

Answer 19

hypertensive crisis

Question 20

ChAT enzyme - meaning and action

Answer 20

Choline acetyltransferase

Choline + Acetyl-CoA –> ACh