pharmacology of pain lecture 2

Question 1

vr1 receptor is equal to what

Answer 1

capsaicin receptor

and TRPV1

Question 2

what is the structure of capsaicin

and other properties

Answer 2

aromatic ring - amide bond - aliphatic side chain
colourless and odourless
soluble in alcohol

Question 3

what does capsaicin selectivly activate and what does it cause

Answer 3

C fibres

cause sensation of heat and pain

Question 4

TRP receptor structure

Answer 4

4 subunits
6 tmd
1 re-enterance loop between 5 and 6 and this forms the pore

Question 5

(TRP)the re-entering loop does what

Answer 5

its a proton sensor

Question 6

(TRP) c termini does what

Answer 6

temp sensor

Question 7

(TRP) n teminus contains

Answer 7

ankyrin repeats for protein protein interaction
it is long
phosoporylation of this reigion via PKA/C activates/ sensitises

Question 8

what does activation of trpv channels cause

Answer 8

local release of sub p and cgrp
leading to intense response to vasculature
increase permeability and vasodilation

Question 9

what happens if there is a reduction in temp threshold in trpv activation

Answer 9

contributes to further inflammation and thermal hypersensitivity

Question 10

trpv is

Answer 10

polymodal

and very high ca2+ cause toxicity

Question 11

caspacin effect on trpv1 receptor

3 points

Answer 11

activates it causing NA+ and Ca2+ influx = depol
large influx of Ca2+ in periphery of nerve terminal cause peptide release (sub p and cgrp)
causing vascular and other physiological responses

Question 12

trpv1 also response to

Answer 12

temp above 42oC

Question 13

in the presence of capsaicin ca2+ permiability is

Answer 13

25:1

Question 14

2 key excitatory NT

Answer 14

glutamate

sub p

Question 15

what are the glutaminergic ion channels

Answer 15

AMPA (na+ influx)
kainate 
NMDA
diverse and wide ranging role 
autism/ schizophrenia/pain

Question 16

what are the sub p receptors
and it antagonist
where does it act

Answer 16

GPCR
antagonist = neurokinin 1 NK-1
peripheral and central action

Question 17

NMDA receptor how is it activated

and what does it cause

Answer 17

glutamate binds and depolarises to remove Mg block

causes Ca2+ influx

Question 18

activation of NMDA causes

Answer 18

wind up

continuous stimulation of nociceptive neurons summation and increase of synaptic excitability

Question 19

in a prolonged inflammatory response what happens

Answer 19

increase production in nociceptive impulse =
summation and increase in synaptic excitability in secondary neuron=
wind up = increased sense of pain

Question 20

NMDA receptor is an ionotropic receptor what type of antagonists does it have

Answer 20

non competative

competative = glycine