Receptor Theory Flashcards
what are two examples of drugs that do not follow receptor theory?
osmotic diuretics
antacids
what are drugs?
chemical compaund that is administered to produce a desirable outcome / effect
what are two ways in which a drug can bind to its receptor?
weakly binding via van der waals
reversibly bonding i.e. enzyme-substrate binding
what are the four main types of receptors?
ion channels, g-protein coupled receptors, enzymatic receptors, and intracellular receptors
what are the two most important receptor properties for drugs?
must be able to recognise the drug and then transduce the drug effect
what is an agonist?
a drug that binds to receptor to elicit a cellular response
what is an antagonist?
a drug that binds to prevent the action of an agonist
what is drug efficacy?
the ability of a drug to elicit an effect
what is a natural agonsit?
a naturally occuring molecule that binds to a receptor
what is a dose response?
biological response to drug is graded
the systematic relationship between drug concentration and magnitude of response obtained
what is the law of mass action?
rate of chemical reaction is proportional to product of the concentration of reactants
explains and predicts behaviours of solutions in equilibrium
what are the limitations of the law of mass action?
all ligands and receptors are equally available - assumed
binding reversible -assumed
what is occupancy theory?
states that the effect we observe is proportional to number of occupied receptors
what is the baseline response?
what happening before drug and smallest response to smallest dose conc
what is the max response?
tells us the limit output of the system
what is the EC50?
effective agonist conc required to give 50% effect
what is cooperativity?
when binding of an agonist to receptor is alterated if there are other ligands present on same receptor
what is a competitive antagonsit?
a drug that binds reversibly with receptors but no response
what is a PA2 value
estimate of conc of antagonist required to double the conc of agonist necessary to elicit original response
what is a non-competitive antagonist?
binds irreversibly yo form complex and does not elicit response
what is affinity?
measure of conc range over which a drug binds to receptor
what is efficacy?
ability of drug to generate response once bound to receptor
what are three ways to end a response?
receptor desensitisation, receptor internalisation, receptor downregulation.
