Measuring Responce Flashcards
(23 cards)
What is Kd used for?
Measuring the affinity of a drug for a receptor
What is efficacy?
Affinity and intrinsic activity
What is efficacy?
A measurement of response
How are concentration-response relationships plotted?
Log[agonist] vs response
What information can be gained from a concentration-response curve?
Potency and Intrinsic activity
What is potency?
A measure of the concentration of a drug needed to elicit a given effect
What is EC50?
The concentration which gives a maximal response - EC stands for effective concentration
What is isoprenaline?
Modified from adrenaline, additional 2 methyls on the N
What is a full agonist?
Elicits a maximum response even when only a portion of the receptors are occupied
What is a partial agonist?
Cannot induce a maximal response when when all receptors are occupied
What is intrinsic activity?
Ability of the drug-receptor complex to evoke a response.
What is a surmountable antagonist?
Increasing the concentration of agonist will overcome the block
What is thrombin?
A proteinase-activated receptor - the N-terminal becomes an agonist and binds to the receptor, switching it off
What is pA2?
log(Kb) The concentration of antagonist that requires a 2-fold increase in agonist to regain the original response level.
What is the Schild plot?
A pharmacological method of receptor classification - also called pA2 analysis.
What is a non-competitive antagonist?
One in which a conformational change is induced by binding to an allosteric site
What is physiological antagonism?
Functional antagonism - two drugs acting on different sites and eliciting opposing effects
What do serine proteinases do?
Enzymes involved in degradation and signalling of proteinase-activated receptors.
What happens to serine proteinases once activated?
They are permanently switched on so have to be internalised and degraded
What does vorpaxar/Zontivity do?
Acts as a ligand to PAR-1. Prevents thrombin-induced platelet aggregation.
What pathway do Gs linked GPCRs stimulate and what can be monitored as a sign of this?
Adenylyl cyclase - cAMP
What pathway do Gi linked GPCRs inhibit and what can be monitored as a sign of this?
Adenylyl cyclase - cAMP
What pathway do Gq linked GPCRs activate and what can be monitored as a sign of this?
PLC pathway - IP or Ca2+
