Lecture 14 - Signalling Molecules And Drug Targets

Question 1

What is the pneumonic for remembering the targets for signalling molecules?

Answer 1

RITE

Question 2

What does the Pneumonic RITE for signalling molecules stand for?

Answer 2

Receptor
Ion channels
Transporters
Enzymes

Question 3

What is pneumonic for remembering the subclasses of receptors?

Answer 3

K(L)ING

Question 4

What does the pneumonic K(L)ING for the subclasses of receptors stand for?

Answer 4

Kinase Linked Receptors
Ion channels (Ligand gated)
Nuclear/intracellular
G-Protein Coupled Receptors

Question 5

What happens to a Ligand Gated ion channel when a ligand binds to it?

Answer 5

Conformational change

Question 6

What is the structure of a nAChr?

Answer 6

2a subunits
1B subunit
1gamma subunit
1 delta subunit

Question 7

How is the ligand gated ion channel nAChr selectively permeable?

Answer 7

Net charge of the pore is negative so doesn’t allow anions through

Question 8

How does a nAChr change shape when ACh binds to it?

Answer 8

Causes conformational change of the alpha subunits, opens up the kinked chains allowing ions through

Question 9

What are some Ligand Gated Ion Channels?

Answer 9

nAChr
GABA(a)
Glutamate
Glycine

Question 10

What is the affect of nAChr on membrane potential?

Answer 10

Excitatory/depolarisation

Question 11

What is the affect of GABA(a) receptor on membrane potential?

Answer 11

Inhibitory/hyperpolarising

Question 12

What is the affect of Glutamate receptor on membrane potential?

Answer 12

Excitatory/depolarising

Question 13

What is the affect of Glycine receptor on membrane potential?

Answer 13

Hyperpolarising/inhibitory

Question 14

Where are glycine receptors found?

Answer 14

Brain stem and spinal cord

Question 15

Where are glutamate receptors found?

Answer 15

Major excitatory neurotransmitter in the CNS

Question 16

Where are GABA(a) receptors found?

Answer 16

Only really found in CNS

Modulate excitatory input by being inhibitory

Question 17

What agonist can be a short acting depolarising blocker in surgery? (nAChr)

Answer 17

Succinyl choline

Question 18

What antagonists non depolarising blockers can be used for surgery? (nAChR)

Answer 18

Pancuronium
Vecuronium

Question 19

What is a major inhibitor receptor in the CNS?

Answer 19

GABA(a)

Question 20

How many GABAs need to bind to a GABA(a) Receptor?

Answer 20

2

Question 21

What ion is a GABA(a) receptor permeable to?

Answer 21

Cl-

Question 22

What is the main family of drugs that target GABA(a) receptors and what do they do?

Answer 22

Benzodiazepines

Keep GABA(a) receptors open allowing lots of Cl- into cell causing hyperpolarisation

Question 23

What is an anxiolytic?

Answer 23

Something that treats anxiety

Question 24

What are some drugs that treat anxiety, insomnia or used for sedation?

Answer 24

Benzodiazepines:
-Diazepam
-Aplrazolam
-Clonazepam

Question 25

What drug can be used for anaesthesia via IV?

Answer 25

Propofol

Very rapid recovery period

Question 26

What type of ligands bind to Nuclear/Intracellular receptors?

Answer 26

Lipophilic ligands that can pass through the cell membrane

Question 27

What happens to the activated nuclear receptor once the ligand binds?

Answer 27

Activated receptor binds to DNA to regulate gene expression

Question 28

What is the name of the DNA sequence which an activated nuclear receptor bind to?

Answer 28

Hormone Response Element

Question 29

What happens in the AF2 region of DNA when the ligand binds to the HRE (Hormone Response Element) and activates the receptor?

Answer 29

Inhibitory protein lost

Question 30

What Nuclear receptors are often used as drug targets?

Answer 30

Oral contraceptives act as agonists for oestrogen
Immune suppression after organ transplant
Vitamin A Inflammatory diseases affecting skin (acne treatment)
Vitamins A and D therapy