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Brain Anatomy > PHAR232 - Cholergic & Adrenergic Pharmacology > Flashcards

PHAR232 - Cholergic & Adrenergic Pharmacology Flashcards

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1
Q

What are the key receptors that ACh bind to?

A

Nicotinic
Muscarinic

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2
Q

How is acetylcholine synthesised?

A

Choline acetyltransferase (CAT or ChAT) transfers an acetyl group from CoA and binds to choline

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3
Q

REVIEW

A

REVIEW

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4
Q

REVIEW

A

REVIEW

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5
Q

REVIEW

A

REVIEW

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6
Q

REVIEW

A

rREVIEW

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7
Q

Does choline cross the BBB?

A

No

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8
Q

REVIEW AND DRAW OUT??

A
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9
Q

What enzyme breaks DOWN ACh to choline?

A

Acetylcholinesterase (AChE)

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10
Q

What do the autoreceptors (Muscurininc e.g. mAChRs) do?

A
  • Modulate how much ACh is in synaptic cleft
  • act as ‘eyes’ of synapse
    Allow pre-synpatic terminal to know how much ACh is being released
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11
Q

What does the activation of autoreceptors on the presynaptic membrane do?

A
  • INHIBIT ACh release
  • Prevents over-excitation of synapse
  • = feedback regulation
  • Reduces Ca2+ release

NOT ALL PRE-SYNAPTIC NEURONS HAVE MUSCURINIC AUTORECEPTORS ON THEM

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12
Q

BOTOX BOTULINUM TOXINS

A

LEARN AND EVALUATE SUMMARY AT A SYNAPSE

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13
Q

If a neuron is using ACh as a NT what is it referred to as?

A

Cholinergic nerve/neuron

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14
Q

How many subtypes of Muscarinic ACh receptors (mAChRs) are there?

A

5

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15
Q

What is M1, M3 and M5 mAChRs for?

A

M1 = Neurons
M3 = gands/smooth muscle
M5 - CNS, salivary glands

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16
Q

Are all muscarinic Ach Receptors metabotropic?

A

yes all of them

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17
Q

What is the GPCR subtype for and the mechanism of actions of M1, M3 and M5 mAChRs?

A

GPCR subtype = Gq
Gq = PLC-IP3-DAG pathway

– activate phospholipase C (PLC)
– increase IP3 & DAG
– increase IP3-mediated liberation of SR
store Ca+2
– increase DAG-mediated activation of
protein kinase C (PKC)
– excite neurons, increase glandular
secretions, cause smooth muscle
contraction

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18
Q

Where are M2 and M4 receptors ?

A

M2 = cardiac
M4 = CNS

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19
Q

What is the GPCR subtype and mechanism of action for M2 and M4 mAChRs?

A

Subtype: Gi

– inhibit AdCy
– decrease cAMP
– decrease PKA
– close Ca+2 channels
- Increase K+ in SA and AV nodes
= Decrease HR
= Decrease contraction force
= Decrease CO
= Increase PNS

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20
Q

What is the mechanism of action of M1 stimulation?

A

= Gq protein of PNS

= Increase IP3 and DAG
= IP3 = increase Ca++
= Increase Ca++ = increased cell excitability
= Increase excitabilty
= decreased K+ conductance
= Reduced repolarisation
= Increased depolarisation of PNS neurons
= Promote relaxation
= promote memory and cognition

» M1 inhibits K+ conductance = PROMOTES RELXATION (PNS)

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21
Q

Specifically M2 does what?

A

» M2 increases K+ conductance
(important in SA, AV nodes)

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22
Q

Specifically M3 does what?

A

» M3 increases Ca+2 conductance
= Bronchoconstriction

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23
Q

Muscarinic Receptor Effects on the * cardiovascular sys?

A
  • primary parasympathetic mediator
  • slows HR, decrease CO, causes vasodilation
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24
Q

Muscarinic Receptor Effects on smooth muscle (not including blood vessels) do what action?

A
  • increase GI ‘rest and digest’,
    ** bronchoconstriction
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25
Q

Muscarinic Receptor Effects on secretions?

A
  • promotes sweating, lacrimation, salivation,
    bronchial secretion
  • stimulation of exocrine glands
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26
Q

Muscarinic Receptor Effects - eye

A
  • constricts pupillae & ciliary muscles
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27
Q

Are nicotinic receptors metabotropic or ionotropic?

A

Ionotropic

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28
Q

REVIEW NICOTINIC RECEPTORS

A
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29
Q

What is the primary ion the Nicoinic ACh receptors cause for influx?

A

Na+

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30
Q

Is a muscinaric receptor primarily PNS or SNS?

A

PNS

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31
Q

Parasympathomimetics

A

Muscarinic receptor agonists

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32
Q

Muscarinic receptor agonists M1 vs M2
- PNS agonist

A
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33
Q

Muscarinic antagonists - aka parasympatholytic

A
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34
Q

What does atropine do?

A

Inrease AV node transmission

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35
Q

What do muscarinic antagonists do?

A
  • Blocks PNS
  • Increases SNS
  • Inhibits glandular secretions
  • Reduces saliva
  • Increase HR = Increase AV node transmission
  • TACHYCARDIA (high dose)

= BRADYCARDIA (low dose)

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36
Q

M1 & M2 LEARN

A

M1 & M2 LEARN

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37
Q

learn

A

Cholinergic antagonist effects

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38
Q

NORADRENALINE (NA) AND ADRENALINE structure

A

LEARN Catecholamine biosynthesis

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39
Q

Differences of adrenergic receptors

A
  • Structure of the receptors will alter how the GPCR work
  • How they are all regulated is difference
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40
Q

Is adrenaline defined more as a hormone or NT?

A

Hormone

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41
Q

Is Noradrenaline defined more as a hormone or NT?

A

NT

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42
Q

Relies a lot on co-factors

A

LEARN NORADRENERGIC SYNAPSE
- NET inhibitors are the ‘vacuum’ to put NA back into the presynaptic cell
- EMT is the minor inhibitor ‘vaccum’ for post synaptic cell

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43
Q

Do adrenergic receptors also have autoreceptors?

A

Yes

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44
Q

LEARN - Noradreneric synapse

A
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45
Q

Does alpha or beta noradrenergic receptors like NA more?

A

alphas like noradrenaline better

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46
Q
A
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47
Q

Remember that _________ receptors = autoreceptors

A

alpha 2

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48
Q

what does a sympathomimetic drug do?

A

mimic sympathic activity

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49
Q

What does a sympatholytic drug do?

A

Opposes or blocks sympathetic activity
lysis = breakdown

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50
Q

LEARN ADRENERGIC AGONIST EFFECTS

A
  • Adrenalin use in anaphylaxis
  • Adjunct to local anathsethic due to vasoconstriction
  • Low BP due to shock
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51
Q

The main controller of all blood vessels for vasoconstriction is the ________ hormone acting on ________ receptors.

A

Adrenaline
alpha 1 receptors

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52
Q

What receptors on key blood vessels regulate vasodilation?

A

beta 2 receptors (but not a major role)

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53
Q

What is an ANTAGONIST of anaphylaxis creating bronchodilation and vasoconstriction?

A

Adrenalin

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54
Q

What does histamine do to the airways?

A

constriction and widespread vasodilation

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55
Q

Is noradrenaline (NA) a hormone or NT?

A

NT

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56
Q

What is an Indirect-acting sympathomimetic?

A
  • MAO in the gut destroys tyramine
  • If someone is taking MAO- inhibitor will reduce MAO that would breakdown tyramine = parasympathomimetic
  • what else does an MAO disinhibit in the gut??
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57
Q

Would ALPHA 1 ADRENERGIC AGONISTS in SNS or PNS pathways?

A

Increase SNS

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58
Q

LEARN AND DRAW OUT - Adrenergic agonist effects

A

Beta 1 adrenergic agonists flow chart

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59
Q

The physiological effects of B1 adrenergic agonists

A

The effects of beta 2 agonists

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60
Q

The sweat glands and MOST blood vessels only have _____________ innovation

A

sympathetic

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61
Q

Bronchial smooth muscle only has a ___________________ constrictor innervation. (however, it’s tone is sensitive to circulating adrenaline)

A

PARASYMPATHETIC

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62
Q

Resistance artieries have a ____________ vasoconstriction innervation but NO _________________ innervation. Instead, the constrictor tone is opposed by a background release of NO from the endothelial cells

A

sympathetic
parasympathetic

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63
Q

What is he sympathetic adrenoreceptor type on the heart?

A

Beta 1 adrenergic receptors

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64
Q

What is the PNS cholinergic receptor in the heart?

A

Muscarinic (M2)

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65
Q

What does the increase in SNS do in the heart?

A
  • Increase HR
  • Increase contraction force
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66
Q

In the large coronary blood vessels - what adrenoreceptors in the SNS stimulate vasoconstriction?

A

Alpha 1 and 2

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67
Q

What do the small coronary blood vessels and muscle SNS receptors use to stimulate vasodilation?

A

SNS effect = beta 2 adrenoreceptors

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68
Q

What adrenoreceptors do the SNS have on the viscera, skin and brain blood vessels?

A

Alpha 1 adrenoreceptors

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69
Q

What does SNS alpha 1 receptor stimulation on viscera, skin and brain in blood vessels cause?

A

Vasoconstriction

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70
Q

The PNS has NO EFFECT on the blood vessel arterioles, except for?

A

Cholingeric vasodilation at M3 receptors

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71
Q

What is the cholinergic PNS receptor subtype in the heart?

A

M2 cholinergic receptors

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72
Q

Does smooth muscle bronchi viscera have sympathetic fibre innervation?

A

no

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73
Q

How is smooth muscle in the lungs dilated?

A

By circulating adrenaline (epinephrine)
and NA activating beta 2 receptors

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74
Q

What is the receptor subtype in the lungs innervated by adrenaline?

A

Beta 2

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75
Q

Does the SNS or PNS cause vasoconstriction in the lungs?

A

PNS

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76
Q

What receptor in the lungs causes vasoconstriction by the PNS?

A

M3 muscarinic - ACh

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77
Q

What are the 3 adrenergic receptors that are innervated by the GI tract?

A

Alpha 1 & 2
Beta 2

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78
Q

Cholinergic Receptors (Muscarinic):

What GPCR subtypes are:

M1, M3, M5: ___

M2, M4: ___

A

Gq.

Gi

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79
Q

What type of cholinergic receptors is the PNS GI tract innervated by?

A

Muscarinic ACh Rs

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80
Q

Does the SNS or PNS cause relaxation in the uterus?

A

SNS

81
Q

What are the SNS receptors in the uterus?

A

Beta 2 adrenergic receptors

82
Q

Does the SNS dilate or constrict the eye pupil?

A

dilate

83
Q

What is the eye adrenergic receptors that cause dilation by the SNS?

A

alpha 1

84
Q

If the SNS dilates the eye, what is the vasoconstriction cholinergic receptor in the eye?

A

M3 muscarinic ACh

85
Q

What receptor innervation causes renin secretion from the kidneys by the adrenergic SNS ?

A

beta 1

86
Q

Pre-ganglionic neurons are cholinergic or noradrenergic?

A

cholinergic ACh neurons

87
Q

Preganglionic neurons are USUALLY always transmitted via _____ ___ ________

A

Nicotinic ACh receptors

88
Q

Post-ganglionic PNS neurons are _________ and act on _________ receptors in target organs

A

cholinergic
muscarinic

89
Q

Postganglionic SNS are mainly ___________ but have ___________ in the sweat glands

A

noradrenergic
cholinergic

90
Q

NT release is inhibited when _____ channel opening is inhibited or when ____ channel opening is increased.

A

Ca++
K+

91
Q

Presynaptic regulation by receptors linked are by _____ channels

A

Ion

92
Q

The noradrenergic and cholinergic neurons are regulated by ____________ feedback

A

autoinhibitory

93
Q

A cholinergic synapses ACh is rapidly inactivated by _______________

A

acetylcholinesterase

94
Q

Is A

A

DRAW THIS OUT

95
Q

Co-transmission and neuromodulation

A
96
Q

Muscarinic actions closely resemble the effects of __________________ stimulation

A

parasympathetic

97
Q

After the muscarinic effects have been blocked by __________, larger doses of ACh produce nicotine-like effects, including:

  • stimulation of all autonomic ganglia
  • stimulation of voluntary muscle
  • Secretion of adrenaline from the adrenal medulla
A

Atropine

98
Q
A
99
Q

ACh causes generalised ________________, even though most blood vessels have no _______________ innervation

A

vasodilation
Parasympathetic

100
Q

How does ACh indirectly act on vascular endothelial cells?

A

Increases NO
= relaxes smooth muscle

101
Q

Is ACh cholingeric secretion from sweat glands innovated by the PNS or the SNS?

A

SNS

102
Q

Nicotinic receptor subtypes

A

Muscarinic receptor subtypes

103
Q

What type of muscarinic receptor subtype is found in the salivary glands, smooth muscle, GI tract, airway, bladder and blood vessel endothelium?

A

M3

104
Q

What is the cellular response of stimulating M3 receptors?

A
  • Increased IP3
    = Increased Ca++
105
Q

What is the cellular response of M2 receptors in the cardiac tissue?

A
  • Decreased cAMP inhibition
    = Increased cAMP
    = Decreased Ca++
    -=Increase K+
    = PNS relaxation

= CHOLINERGIC INHIBITION OF THE HEART AND CNS AND PERIPHERY

106
Q

What is the cellular response of M1 receptors on neuronal ganglia?

A
  • Increased IP3
  • Increased DAG
  • Depolarisation
  • Slow EPSP
  • Reduce K+ conductance
107
Q

What is a key non-selective antagonist for muscarinic receptors?

A

Atropine

108
Q

Where are M2 receptors found?

A

Cardiac tissue

109
Q

Where are M3 receptors usually found?

A

gandular/smooth muscle tissue

110
Q

What is the primary stimulation of M3 receptors? Excitatory or inhibitory?

A

Excitatory e.g. increased salivation
- Increased bronchial contraction
- Increased sweat

111
Q

mAChRs are GPCRs causing what key 3 things?

A
  • Increased PLC
  • Increase IP3
  • Increased DAG
  • Inhibition of Ad Cy
  • Increased K+
  • Inhibition of Ca++

= PNS STIMULATION

CHECK THIS QUESTION WITH ANNA MARIE - IS IT INHIBITORY OR NOT??? - TEXTBOOK PAGE 178 SAYS THE ABOVE

112
Q

Free choline within the nerve terminal is acetylated by a cytosolic enzyme __________ __________. Which transfers the acetyl group from acetyl Co-enzyme A.

A

choline acetyltransferase (CAT)

113
Q

_________________ is an enzyme present in the presynaptic nerve terminals to hydrolysed ACh into choline + acetate.

A

Acetylcholinesterase

114
Q

Inhibition of cholinesterase causes the accumulation of ______ in the cytosol

A

ACh

115
Q

Where does ACh leak out from the cytosol into the synaptic cleft?

A

via the Choline carrier

116
Q

What enzyme breaks down ACh?

A

Acetylcholine esterase (AChE)

117
Q

Catecholamine Biosynthesis - REVIEW

A

Structure of Adrenergic Receptors

118
Q

Is noradrenaline a NT or hormone?

A

NT

119
Q

Is adrenaline a hormone or NT?

A

hormone

120
Q

noradrenaline & adrenaline best recognised for effects on heart and lungs. What beta receptors are associated with an increased HR, increased force of contraction ?

A

beta 1 receptors

121
Q

What receptor is associated with vasoconstriction by noradrenaline and adrenaline?

A

Alpha 1

122
Q

What receptor is associated with bronchodilation by noradrenaline and adrenaline?

A

beta 2

123
Q

precursor for both noradrenaline & dopamine =

A

tyrosine

124
Q

Noradrenergic Synapse

A
125
Q

5 steps associated with adrenergic and cholinergic synapses:

A
  1. synthesis
  2. packaging
  3. release
  4. signal termination
    5 control of NT release
126
Q

Noradrenergic Synapse -
* synthesis = multistep process

A
127
Q

like ACh, synaptic vesicles containing NA triggered to move by incoming AP from axon
& absolutely controlled by_____ influx

A

calcium

128
Q

unlike ACh, NA signal termination does NOT use an_______

A

enzyme

129
Q

What do Noradrenergic synapses use for NA signal termination?

A

(NET)

  • Norepinephrine transporter
130
Q

What does NET do to stop NA signalling?

A

acts like vacuum cleaner to remove all NA from the synapse to stop NA signalling

131
Q

Activation of ___________ receptors stop NA release in noradrenergic synapses?

A

Autoreceptors at NA synapse

132
Q

What type of receptors are the NA autoreceptors?

A

A2 adrenergic receptors

133
Q

Noradrenergic Synapse - review

A

built-in neuromodulator of NA
signalling

134
Q

Catecholamines what are some effects mediated by adrenergic receptors:

A

dilate pupil (a1) or relax ciliary muscle of eye (b2)
* constrict blood vessels (a1)
* dilate blood vessels (a2 & b2)
* inhibit histamine release from mast cells in lungs
(b2)
* decrease gut motility (a1)
* sweating (a1) – note that primary effect = ACh
* goosebumps (a1)
* monitor adrenergic neurotransmitter release (a2
receptors decrease release; b2 receptors increase
release)
» Remember: a2 receptors = autoreceptors

135
Q

Are a2 receptors autoreceptors?

A

Yes

136
Q

What is sympathomimetic?

A

mimics sympathetic
(adrenergic)

137
Q

What is sympatholytic?

A

oppose/block sympathetic

138
Q

ADRENERGIC AGONIST EFFECTS - DRAW OUT

A
139
Q

what does agonist activation of a1 adrenergic receptors do?

A

= Increase SNS
= Vasoconstriction
= Pupil dilation
= Decreased GIT
= Increase B glucose
= Sweating
= Goosebumps

140
Q

what does agonist activation of beta-1 adrenergic receptors do?

A

= INCREASE SNS

= Increased cardiac acceleration
= Increase HR
= Increase SV
= Increase CO
= Decrease GIT
= Lipolysis
= Increase renin = increase BP

141
Q

what does agonist activation of beta-2 adrenergic receptors do?

A

= Increase PNS

= Bronchodilation
= Vasodilation
= Increase blood glucose
= Pregnant uterus relaxation
= Mast cell stabilisation

= RELAXATION

142
Q

activation of the adrenal medulla is by ACh acting on________ but as part of
sympathetic 2-neuron chain

A

nAChRs

143
Q

What receptors does adrenaline stimulate?

A

a1, a2, b1, b2

  • stimulates all subtypes of adrenergic receptors
  • therefore causes all major effects when SNS is activated
144
Q

REMEMBER: Adrenaline: net direct effect on BP from blood vessel changes is________ because of
balance between constriction/dilation

A

small

145
Q

What are the effects of adrenaline on the cardiovascular system?

A

increase HR and contraction force = b1 receptor

  • vasoconstriction of majority of blood vessels =
    a1 receptor
  • vasodilation of other key blood vessels = b2
    receptors
  • promote renin release from kidneys, increasing
    BP indirectly = b1 receptors
146
Q

Is adrenaline a physiological antagonist or agonist of anaphylaxis?

A

Physiological ANTAGONIST
= Increased bronchodilation
= Increased vasoconstriction

147
Q

What are the side effects of too much adrenaline?

A

SERIOUS CARDIOVASCULAR EFFECTS

  • Tachycardia
  • Increased BP
  • Increased vasoconstriction
  • Potential ischaemia/necrosis
148
Q

What is they key difference between adrenaline and NA?

A

= receptors with which they interact

  • noradrenaline has small effect on b2 receptors
    vs other adrenergic receptors

» since b2 receptors responsible for
vasodilation, NA only really
vasoconstricts

149
Q

KNOW AND REVISE

A

Indirect-acting Sympathomimetics

150
Q

How do Indirect-acting Sympathomimetics work?

A

compete with NA at uptake proteins and
vesicle transporters

  • outcompete NA at uptake 1 to prolong its
    effects at synapse
  • once inside presynaptic cell, outcompete NA
    for transport into vesicles

» leads to passive, regular release of NA
from cell

151
Q
  • classic agents are for indirect-acting sympathomimetics are ________ and ________
A

amphetamine, tyramine

152
Q

KNOW AND DRAW OUT

A

Think of alpha 1 receptors as INCREASED SNS
What happens when you’re on amphetamines

153
Q

The effects of alpha-1 agonists

A

KNOW AND DRAW OUT

154
Q
A

The effects of alpha-2 agonists

155
Q

What is a rate-limiting step at a synapse?

A

The rate-limiting step in a process or reaction is the slowest step, which determines the overall rate or speed of the entire process.

156
Q

wha are the 4 key summary steps for a synapse?

A
  • dedicated synthesis
  • rate-limiting step for control of synaptic control
  • method of rapid termination of signal
  • means of feedback regulation (=autoreceptors)
157
Q

Muscarinic ACh Receptors (mAChRs) mechanism of action

A

= activate PLC
= increase IP3 and DAG
= Increase IP3 - mediated liberation of SR store Ca++
= Increase DAG-mediated activation of PKC
= Excite neurons
= Increase glandular secretions, cause smooth muscle contraction

158
Q

M1 ACh neurons associated with?

A

M1 (neurons)

159
Q

M3 ACh neurons associated with?

A

glands/smooth muscle

160
Q

M5 ACh neurons associated with?

A

CNS, salivary glands

161
Q

M2 ACh neurons associated with?

A

Cardiac

162
Q

M4 ACh neurons associated with?

A

CNS

163
Q

What do M2 (cardiac) and M4 (CNS) use Gi type GPCRs to INHIBIT ____ for cell inhibition

A

Ad Cy

164
Q

What do Gi GPCR do on M2 and M4 cells?

A

INHIBITION

= Inhibit Ad Cy
= Decrease cAMP
= decrease PKA
= Close Ca++ channels

165
Q

What additionally happens upon Gi GPCR to inhibit M1 cells

A

ADDITIONAL: Inibits K+ conductance

INHIBITION

= Inhibit Ad Cy
= Decrease cAMP
= decrease PKA
= Close Ca++ channels

166
Q

What additionally happens upon Gi GPCR to inhibit M2 CARDIAC cells

A

ADDITIONAL: Increase K+ conductance (important in SA and AV nodes)

INHIBITION

= Inhibit Ad Cy
= Decrease cAMP
= decrease PKA
= Close Ca++ channels

167
Q

What mAChR effects have on the cardiovascular system?

A
  • PRIMARY SNS MEDIATOR
  • Slows HR
  • Decrease CO
  • Causes VASODILATION
168
Q

What mAChR effects have on the smooth muscle system? (not including blood vessels)

A
  • INCREASE SNS
  • Increase parastalsis
  • BRONCHOCONSTRICTION
169
Q

What mAChR effects have on the secretions?

A
  • Promotes sweating
  • Lacrimation (tears)
  • Salivation
  • Bronchial secretion
  • Exocrine gland stimulation
170
Q

What mAChR effects have on the eyes?

A
  • CONSTRICTS pupils
171
Q

Nicotinic ACh Receptors

A
172
Q

How many alpha subunits are on nAChRs?

A

2

173
Q

How many ACh bind to nAChRs for activation?

A

2

174
Q
A
175
Q

What would be clinical uses for parasympathomimetics?

A
  • Treat glaucoma
  • Slow HR
  • Stop atrial tachycardia
  • Stimulate bladder emptying
  • Stimulate GI activity
176
Q

What receptors are used on the target organ of PNS?

A

mAChRs

177
Q

Sympathomimetic effects (muscarinic receptor AGONIST EFFECTS)

A

MUSCARINIC RECEPTOR AGONIST FLOW CHART -DRAW OUT

178
Q

MUSCARINIC RECEPTOR AGONIST FLOW CHART -DRAW OUT

A
179
Q

Could AChE inhibitors be classified as parasympathomimetics?

A

yes

180
Q

What is the MAIN mAChR ANTAGONIST?

A

atropine

181
Q

What is another term for mAChR antagonist?

A

parasympatholytic

182
Q

Is choline readily transported across the BBB?

A

no

183
Q

How does the brain gets major source of choline?

A

By recycled ACh

Catabolism *(breakdown) of phosphatidyl-choline

184
Q

What is the rate limiting step in ACh signalling?

A

Availability of choline at synapse

185
Q

What does the activation of autoreceptors do at the ACh synapse?

A

Inhibit ACh release
= feedback regulation

186
Q

What do botulinum toxins do to ACh in the presynaptic synapse?

A

Destroy proteins involved in vesicle mobilisation *enzymes

  • Stop/reduce ACh release
187
Q

Does M3 increase or decrease Ca+ conductance upon AChR activation?

A

Increases Ca++ Conductance

188
Q

blocking parasympathetic activity results 3 key things:

A
  • Dilates pupil & impairs near vision
  • Inhibits GI motility
  • Relaxes smooth muscle INCLUDING
  • BRONCHIOL RELAXATION
  • BLADDER relaxation (retention)
189
Q

M1 and M2 muscarinic ANTAGONISTS - DRAW THIS OUT

A

M1 and M2 muscarinic ANTAGONISTS - DRAW THIS OUT

190
Q

Why would a muscarinic antagonist be used as a pre-op medication for surgery?

A
  • reduce bronchial & salivary secretions
  • Prevent reflex bronchoconstriction
191
Q

Why would a muscarinic antagonist (atropine) be used as an antidote for toxicity?

A

Toxins often have AChE inhibitors

youtube

192
Q
A
193
Q

CHOLINERGIC ANTAGONISTIC EFFECTS at muscarinic receptors - KNOW AND DRAW OUT

A
194
Q

What synthesises ACh?

A

choline acetyltransferase (CAT or ChAT)

transfers acetyl group from
coenzyme A (CoA)

195
Q

What is the vesicular ACh transporter (VAChT) doing?

A

= H+-ATPase pump

196
Q

What is the rate limiting step of ACh?

A

Na+-dependent high affinity
choline uptake

197
Q

What would anticholinesterases e.g. neostigmine o to ACh?

A

= Increase ACh
= Inhibit the activity of acetylcholinesterase (AChE)
= Increase ACh in synaptic cleft

  • = reveral of non-depolarising muscle relaxants during anaesthesia
198
Q

What are 6 KEY AREAS to focus on for synaptic drug targeting

A
  1. NT Synthesis
  2. Vesicular packaging
  3. Release
  4. Post-synaptic action
  5. Autoreceptor monitoring
  6. Signal Termination
  7. Ca++ VG channels

Brain Anatomy (59 decks)

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