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Flashcards in Drugs on synaptic transmission Deck (29):
1

what are the various steps in neurotransmission

1) synthesis
2) storage
3) arrival of action potential at pre-synaptic bouton
4) depolarisation of terminal to activate vgccs
5) release (calcium dependant)
6) neurotransmitter binds to receptors
7) uptake/breakdown of neurotransmitter

2

what do local anaesthetics and anti epileptics do

they block voltage gated sodium channels so no action potentials can propagate down the axons.

3

what do analgesics do

block voltage gated calcium channels so that neurotransmitters can't be released

4

where is Ach synthesised

NMJ
ganglia
parasympathetic post-ganglionic fibres
CNS

5

what is the enzyme that synthesises acetylcholine

choline acetyltransferase (ChAT)

6

what is acetyl coA produced by

cellular respiration

7

what are the consequences of ChAT inhibitors

(fa64a)
they are ChAT inhibitors - very dangerous biological weapons - all ganglia would not work and NMJ would not work

8

what does the botulism toxin do (chloristrodium botulism)

degrades Ach containing vesicles so ANS and motor fibres are inhibited

9

what does beta bungarotoxin do

type of snake venom
prevents Act release

10

what is acetylcholine broken down (inactivated) by

acetylcholinesterase (AchE) loaded on post-synaptic membrane

11

what are anti-choline esterases

drugs that enhance on prolong chmlinergic transmission
cause increase in parasympathetic actions e.g. bradycardia, bronchoconstrictoin etc.

12

short actin drugs

e.g. edrophonium
used for diagnostic purposes
improves myasthenia gravis

13

medium acting drugs

e.g. neostigmine
used to reverse neuromuscular block after surgery

14

long acting drugs

irrervsible
new AchE needs to be synthesised and so is very dangerous

15

where is A and NA synthesised

CNS
sympathetic post ganglionic fibres and
adrenal medulla

16

what is the equation to get DOPA decarboxylase

tyrosine + DOPA > DOPA decarboxylase (rate limiting step)
uses tyrosine hydroxylase in cytoplasm

17

how do you get dopamine

DOPA decarboxylase > Dopamine
uses dopamine decarboxylase

18

how do you get NA

Dopamine > NA
uses dopamine hydrolase

19

how do you get A

NA > A
uses PNMT in adrenal medulla

20

how and where is NA stored

in vesicles in a complex with ATP
because ATP is also a nuerotransmiter at noradrenergic synapses

21

what is Resperpine

a drug that disrupts the complex between ATP and NA so that NA leaks out of the cytoplasm
this reduces the ability for vesicles to take up NA
causes a reduction in adrenergic transmission
used as early treatment for hypertension

22

what is guanethidine

an adrenergic neuron blocker
inhibits release of NA

23

how is NA removed

by reuptake unchanged back into pre-synaptic terminal

24

high affinity carrier =

uptake 1 (neuronal sites, ANS, CNS)

25

low affinity carrier =

uptake 2 (non-nueronal sites)

26

how is NA metabolised in neurones

by Monoamine oxidase (MAO)

27

how is NA metabolised in non-neuronal sites (e.g. adrenal medulla)

cathecol-O-methyltransferase (COMT)

28

what drugs may target this uptake mechanisms

Cocaine
tricyclic anti depressant
(inhibit uptake 1 = increase adrenergic transmission)

29

what is MAO inhibitor used as

an antidepressent