QUIZLET Unit 2 - Drug Receptors and Pharmacodynamics (1) Flashcards
Actions/effects of the drug on the body
Pharmacodynamics
Specific molecules in a biologic system with which drugs interact to produce changes in the function of the system.
Receptors
It is the fundamental event that initiates the action of the drug
Interaction between the drug and the receptor
It mediates the actions of both pharmacologic agonists and antagonists
Receptors
Specific binding region of the macromolecule.
Receptor site or Recognition site
Best characterized drug receptors
Regulatory proteins
Receptor that Mediates the action of endogenous chemical signals like neurotransmitters, autacoids, and hormones.
Regulatory proteins
Receptor thatInhibited (or less commonly, activated) by binding a drug
Enzymes
dihydrofolate reductase, the receptor for methotrexate are examples of this receptor
Enzymes
Na+ /K+ ATPase, the membrane receptor for digitalis are examples of this receptor
Transport Proteins
tubulin, the receptor for colchicine, an anti-inflammatory drug are the examples of this receptor
Structural Proteins
Molecules that translate the drug-receptor interaction into a change in cellular activity
Effectors
TRUE or FALSE: Some receptors are also effectors.
True
Transmembrane signaling mechanism in which the drug crosses the plasma membrane and acts on intracellular receptor
Lipid-soluble
Transmembrane signaling mechanism in which it regulates the opening of the ion channel (e.g. GABA, excitatory acetylcholine
Ligand-gated transmembrane ion channel
Transmembrane signaling mechanism in which it modulates production of an intracellular second messenger [e.g., catecholamine (epinephrine)].
Transmembrane receptor is coupled with an effector enzyme by G protein
G protein Receptor for β-Adrenergic amines, histamine, serotonin, glucagon, and many other hormones
Gs
G protein receptor for α2-Adrenergic amines, acetylcholine (muscarinic), opioids, serotonin, and many others
Gi1, Gi2, Gi3
G protein receptor for Odorants (olfactory epithelium)
Golf
G protein receptor for Neurotransmitters in brain (not yet specifically identified)
Go
G protein receptor for Acetylcholine (muscarinic), bombesin, serotonin (5-HT2), and many others
Gq
G protein receptor for Photons (rhodopsin and color opsins in retinal rod and cone cells)
Gt1, Gt2
Conservation of water by the kidneys mediated by
vasopressin
Mobilization of stored energy (breakdown of carbohydrates in the liver stimulated by
Catecholamines
Mediates hormonal responses
Cyclic Adenosine Monophosphate (cAMP)
Calcium homeostasis by
parathyroid hormone
Measure of drug efficacy
Emax
Few signaling roles in a few cell types like the intestinal mucosa and vascular smooth muscle cells
Cyclic Guanosine Monophosphate (cGMP)
Heart rate and contraction by
beta-adrenomimetic catecholamine
Bind to receptors linked to G proteins while others bind to receptor tyrosine kinases.
Calcium and Phosphoinositides
Causes relaxation of vascular smooth muscles by a kinase-mediated mechanism
cGMP
Maximal response that can be produced by a drug
Emax
Response of a particular receptor-effector system is measured against increasing concentration of a drug.
Graded Dose-Response Curve
TRUE or FALSE: The smaller the EC50, the greater the potency of the drug
True
Measure of drug potency
EC50
Half-maximal effective concentration
EC50