Drugs + Synaptic Transmission

Question 1

Pain transmission can be inhibited by…

Answer 1

Sodium channel blockers e.g. lignocaine

Question 2

What are 2 types of SNARE proteins?

Answer 2

V snares

T snares

Question 3

What is name of vesicle associated membrane protein called?

What do they interact with?

Answer 3

VAMP/ Synaptobrevin

They interact with T Snares

Question 4

What are 2 examples of T snares?

Answer 4

SNAP25 + syntaxin-1

Question 5

What is SNARE-pin?

Answer 5

Complex between V snare + 2 T snares

Question 6

What stabilises SNARE-pin?

Answer 6

Calcium binds to synaptotagmin

Question 7

What are 2 parts that botulinum toxin is formed from?

Answer 7

One binds to glycoprotein to cholinergic neurones allowing toxin entry
One cleaves SNAP25 or VAMP

Question 8

What produces botulinum toxin?

Answer 8

Anaerobic bacterium clostridium botulinum

Question 9

What can break the botulinum toxin?

Answer 9

High levels of heat

Destroyed by heating of >85 degrees calcium

Question 10

Choline uptake is directly inhibited by……

Answer 10

Hemicholinium

Question 11

Storage of Ach in vesicles can be prevented by……. which also displaces Ach

Answer 11

Vesamicol

Question 12

What does cholinesterase inhibitors do?

Answer 12

Increase Ach levels in vicinity of receptor so lots of activation of receptors therefore produces lots of cellular effects . They are different speeds of acting ranging from short acting to medium to irreversible acting
Short acting : edrophonium
Medium acting: neostigimine
Irreversible acting: parathion, ectothiophate, dyflos

Question 13

What does the drug reserpine do?

Answer 13

Stole uptake of noradrenaline or its metabolites into vesicles

Question 14

What does drug guanethidine do?

Answer 14

Displace adrenaline from vesicles

Question 15

What does cocaine, desipramine and imipramine do?

Answer 15

Work by blocking noradrenaline uptake mechanism back into nerve. There is increase in concentration of noradrenaline so there is more activation of receptors

Question 16

What does Amphetamine, tyramine + ephedrine do?

Answer 16

Doesn’t inhibit directly uptake mechanism but it is taken up by the uptake mechanism. As consequence, noradrenaline cannot compete + it is not taken up. It displaces noradrenaline from vesicles therefore less noradrenaline is taken up. More noradrenaline leaking out of cell

Question 17

What does MOA inhibitors do?

Answer 17

Inhibit enzymes that degrade noradrenaline