P3: Guinea Pig Ileum

Question 1

Plotting a does-response curve

Answer 1

• y: contraction (mm)
• x: log10[…] (M)

Question 2

Agonist

Answer 2

Drug that binds to the receptor, producing a similar response to the intended chemical and receptor

Question 3

Antagonist (define, plus types)

Answer 3

Drug that binds to rec., either on primary site or otherwise, altogether stopping the receptor form producing a response
Can be competitive or non-competitive; competitive agonist shifts curve right without affecting max response whereas non-competitive i.e. irreversible antagonist lowers max response w/ same starting point

Question 4

Types of agonist

Answer 4

• endo (e.g. hormones, NTs) vs exogenous (e.g. drugs)
• full vs partial (same receptor, different levels of response)
• inverse (same rec. but exact opposite response)
• irreversible (permanently covalently bond to rec.)
• selective
• co-agonists (requires 2 or more agonists to elicit a particular biological response)

Question 5

Agonist potency

Answer 5

• Level of agonist require to induce a desired biological response
• Often measured by EC^50 value, which is concentration required to induce half the maximal response