Dose-Response Curves

Question 1

What are the functional responses in vivo?

Answer 1

• Change in heart rate
• Change in blood pressure
• Homrone secretion, e.g. insulin
• Nerve action potential frequency

Question 2

What are the functional responses in vitro?

Answer 2

Isolated tissue:

 - smooth muscle contraction
 - brain slice transmitter release
 - nerve compound action potential

Single cells:

 - Membrane potential change
 - Membrane ion channel curren, [cAMP], [Ca2+], [cGMP], [H+]

Multicellular assays:

 - Cell profileration
 - Reporter gene product

Question 3

Define p(AR)

Answer 3

Receptor occupancy - the proportion of receptors occupied

Question 4

State the equation for p(AR), the receptor occupancy.

Answer 4

k + 1
A + R <======> AR
k - 1

Question 5

State the law of mass action.

Answer 5

“The rate of a reaction is proportional to the product of the concentrations of the reactants.”

Question 6

What are the assumptions of the p(AR) equation?

Answer 6

1. The law of mass action is applied

2. The system is at equilibrium

Question 7

State the Hill-Langmuir Equation

Answer 7

[A}
p(AR) = —————
K(A) + [A}

Question 8

State some variations of the Hill-Langmuir Equation

Answer 8

p(R) + p(AR) = 1

        K(A) p(R) =  ------- p(AR)
         [A}