Week 1 - Pharmacodynamics and Cell Signalling

Question 1

Details a Full Agonist

Answer 1

• Produces maximum response

- High Efficacy

Question 2

Details of Partial Agonist

Answer 2

• Cannot achieve maximal response.

- Low Efficacy

Question 3

Action of a Inverse Agonist

Answer 3

• Decreases receptor activity (uncommon)

Question 4

Action of an Agonist

Answer 4

• Binds to a receptor and activates it.

Eg: noradrenaline

Question 5

Action of an Antagonist

Answer 5

• Binds to a receptor and produces no response

Eg: Atenolol (B-blocker)

Question 6

Actions of a Reversible Antagonist

Answer 6

• Binds then quickly dissociates
• may compete with agonist for binding site
• surmountable

Question 7

Actions of an Irreversible Antagonist

Answer 7

• binds then dissociates very slowly
• inactivates a proportion of receptor
• not surmountable (not affected by agonist concentration) population

Question 8

Action of a Competetive Antagonist

Answer 8

• bind to same site an agonist uses

- can alter shape of receptor to make it inaccessible to agonist.

Question 9

Action of a Non-competetive Antagonist

Answer 9

• binds only when agonist is not bound

Question 10

Action of an Uncompetitive Antagonist

Answer 10

• binds even when agonist is bound

Question 11

What is Affinity?

Answer 11

the tendency to bind to a receptor

Question 12

What is Efficacy?

Answer 12

the ability to initiate a response once bound

Question 13

What is Intrinsic Activity?

Answer 13

the capacity of a single drug-receptor to evoke a response

Question 14

What is Pharmacokinetics?

Answer 14

Mechanisms of a drugs:
absorption, distribution and elimination
(i.e. the action of the body on the drug)

Question 15

What is Pharmacodynamics?

Answer 15

The mechanism of action of drugs on life processes

i.e. the actions of the drug on the body

Question 16

What is a Concentration-effect curve?

Answer 16

the relationship between

drug concentration and its pharmacological response

Question 17

What is Potency?

Answer 17

• the concentration that produces a certain
  pharmacological response
• Determined by affinity and efficacy

Question 18

What is EC50?

Answer 18

The concentration of a drug to produce 50% of a maximum response.
(measures potency)

Question 19

Example of Full Agonists and their receptor

Answer 19

morphine, heroine, codeine

at the mu opioid receptor

Question 20

Example of Antagonist and their receptor

Answer 20

naloxone and naltrexate

at the opioid receptors

Question 21

Example of Partial Agonist and their receptor

Answer 21

methadone

at opioid receptors

Question 22

Types of True Receptors

Answer 22

• Ligand-gated ion channels
• G-protein coupled
• Kinase-linked
• nuclear

Question 23

Examples of Ligand-gated Ion Channels receptors

Answer 23

• GABA A and C
• Glycine
• 5-HT3
• Purine P2x

Question 24

What is the location and coupling of a Ligand-gated Ion channel, giving an example?

Answer 24

• membrane bound
• direct coupling
  Eg. nicotinic ACh receptor; GABA

Question 25

What is the location and coupling of a G-protein-coupled receptors, giving an example?

Answer 25

• membrane bound
• channel or enzyme
• G-protein
  Eg. muscurinic ACh receptor; all adrenoceptors

Question 26

What is the location and coupling of a Kinase-linked receptors giving an example?

Answer 26

• membrane bound
• direct coupling
  Eg. insulin; growth factors; cytokines

Question 27

What is the location and coupling of a Nuclear receptor giving an example?

Answer 27

• Itracellular
• gene transcription
• via DNA
  Eg. steroid; thyroid receptors

Question 28

What are the 3 stages of Cell signalling?

Answer 28

Reception
Transduction
Response