Term
What is the definition of pharmacodynamics? |
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Definition
The study of the biochemical and physiological effects of drugs and their mechanisms of action |
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Term
What physical characteristics of drug molecules determine binding specificity? |
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Definition
Drug size, shape, stero-isomerism (only one optical isomer), and polarity |
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Term
What pulls ligands closer to the receptor? What couples the ligand to the receptor? |
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Definition
Ionic bonds bring the ligand close to the receptor, hydrogen or van der waals forces couple the ligand to the receptor |
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Term
What is binding affinity (Kd) |
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Definition
A measurement of how readily a molecule will bind to a receptor, also the concentration of drug required to bin 1/2 of the receptors in a fixed population (high Kd means low affinity) |
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Term
What is the law of mass action? |
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Definition
L + R <-> LR* -> biological response (L = ligand, R = receptor) |
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Term
How does Le Chatelier's theory apply to receptor theory? |
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Definition
A change in the concentration of the drug or the receptor will shift the biological response one way or another |
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Term
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Definition
The strength of the attraction between a ligand and a receptor |
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Term
How do you calculate the equilibrium disassociation constant (Kd) of affinity? |
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Definition
Kd = [L][R]/[LR], you can find it on a graph by looking at the concentration of the drug required to occupy 50% of the receptors |
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Term
What is efficacy in receptor theory? |
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Definition
A characteristic property of a ligand to induce the receptor to adopt an active conformation to generate a biological response (varies between 0-1) |
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Term
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Definition
A substance which binds to a receptor and produces a biological response |
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Term
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Definition
Substance capable of generating the maximum biological response a system can achieve by activating 100% or less of the receptors, affinity and efficacy = 1 |
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Term
What is a partial agonist? |
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Definition
Substance that produces, even at its highest concentration and 100% receptor occupation, less than the maximum response achievable by a system, affinity is and efficacy are between 0-1 |
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Term
What is an inverse agonist? |
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Definition
A substance that produces a decrease int he basal activity of a system |
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Term
What are allosteric agonists or enhancers? |
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Definition
Chemical compounds that increase the affinity and/or efficacy of agonists for receptors by binding and altering receptor conformation |
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Term
What are the different types of antagonists? |
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Definition
Chemical and physiologica |
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Term
What is indirect antagonism? |
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Definition
A substance that inhibits a biological response by acting at a site beyond the receptor, can antagonize agonists acting through more than one receptor |
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Term
What are competitive antagonists? |
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Definition
Most common, endogenous agonists and exogenous antagonists compete for a binding site on the receptor, has affinity but no efficacy |
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Term
What characterizes equilibrium competitive antagonists? |
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Definition
Reversible, antagonism increases at increased concentrations, can be overcome by increasing the amount of agonists |
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Term
What characterizes nonequilibrium competitive antagonists? |
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Definition
Binds irreversibly to receptor via covalent bond, antagonism increases with concentration, cannot be overcome by increasing agonist amount |
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Term
What distinguishes allosteric agonists? |
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Definition
Reduces affinity or efficacy of agonists by binding receptors on sites distinct from the agonist binding site |
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Term
What is a dose-response curve? |
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Definition
Graphical representations of the relationship of the quantity of a substance (drug or ligand) to the graded effect that the substance has on a biological system |
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Term
What is a graded response? |
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Definition
A response is one that changes proportionately with each single dose of drug given with each dose producing a single tissue response |
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Term
What do quantal dose-response curves represent? |
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Definition
The "all or nothing" theraputic endpoints of a drug based on dosage |
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Term
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Definition
A comparison of the relative effectiveness of drugs acting by similar mechanisms by comparing ED50 values |
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Term
Intrinsic activity is another name for what? |
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Definition
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Term
How is equilibrium competitive antagonism graphically represented? |
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Definition
Rightward shift (apparent decrease in potency) of the dose-response curve while still being able to achieve a maximum response (albeit at a much higher dose of agonist) |
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Term
How is nonequilibrium competitive antagonism graphically represented? |
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Definition
Downward shift, maximum response is impossible to attain regardless of dose |
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Term
What is indirect antagonism? |
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Definition
Antagonist that inhibits the generation of a biological response by acting at some point down stream of the receptor (i.e. with components of its signal transduction cascade), can be reversible or irreversible |
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Term
What receptors are adrenergic receptors? |
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Definition
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Term
What receptors are serotonergic receptors? |
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Definition
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Term
What receptors are muscarinic cholinergic (Ach) receptors? |
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Definition
M1, M2, M3, M4, M5 receptors |
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Term
What receptors are histamine receptors? |
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Definition
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