Receptors 3 Flashcards
affinity
tells us how well the drug interacts with the receptor
Specificity
how selective is a drug binding to one type of receptor but not to other types of receptors?
efficacy
tells us how effective a drug is at producing a particular receptor response
Potency
tells us how much of the drug is required to produce an effect
agonist
drug that activates receptor
Antagonist
a drug that blocks a neurotransmitter to bind to receptor
how can affinity be measured?
can be measured using a binding assay. This is a direct measure of the physical interaction between a drug and a receptor
A drug may bind to many biological targets, those with high affinity is called?
specific binding
A drug may bind to many biological targets, those with lower affinity is called?
nonspecific binding.
How does nonspecific binding increase?
it will increase with high concentration of radioligand
How do you find specific binding?
subtract non-specific binding from total binding to find specific binding
what is Kd?
equilibrium dissociation constant
How do you find Kd? (equation)
tendency of RD complex to dissociate / tendency of R & D to form RD complex
What is the releation between Kd and RD?
the smaller Kd the less likely RD to dissociate, the higher the affinity of D for R
Kd on a curve means what?
drug concentration when 50% of receptors bound with the drug
the smaller the Kd value = ?
higher affinity for receptor
what is EC50 ?
the concentration of a drug that produces 50% of maximal response
Efficacy reflects what?
the upper limit (maximal response) achieved by a drug on the dose response curve
Potency is inversely correlated to what?
EC50
in regards to potency and EC50 relationship, Higher Potency =?
smaller EC50 concentrations
when agonist binds to a receptor and activates signaling, how does that shift equilibrium?
it shifts equilibrium towards the active state
When antagonist binds to the receptors but does not activate signaling, how does that change the equilibrium?
does not change the equilibrium between active and inactive states of receptor, but it can prevent agonist binding.
Inverse agonist
produces a response opposite of that induces by full agonists
How does inverse agonist effect equilibrium when bound to receptor?
shifts equilibrium towards the inactive state
