Receptors and the Effects of Drugs

Question 1

What are competitive antagonists

Answer 1

Bind reversibly at same site as agonist
Parallel shift to right of agonist does/response curve
Partial agonist can also behave as competitive antagonists

Question 2

What are irreversible antagonists

Answer 2

Bind irreversibly at the same site as agonist
Reduce receptor numbers
Reduce maximal response

Question 3

What is the evidence for spare receptors

Answer 3

Initial shift to the right of curve with no decrease in max response

Question 4

What are allosteric antagonists

Answer 4

Bind reversibly at distinct site from agonist
Reduce agonist affinity
Decrease response

Question 5

What are channel blockers

Answer 5

Bind inside channel to prevent passage of ions

Question 6

What are physiological antagonists

Answer 6

Produce non-selective suppression of response

Question 7

What is desensitization

Answer 7

Prolonged/repeated exposure to agonist can reduce response to drug