U2.1 DRG PHARMACODYNAMICS & RECEPTORS Flashcards
Actions or effects of the drug on the body
Pharmacodynamics
plays a major role in deciding whether a group is appropriate therapy for a particular symptom or disease
Pharmacodynamics
Specific molecules/target molecules of the drug so that they could interact with the body that produce changes in the function of the system
Receptors
Determine the quantitative relations between dose or concentration of drug and pharmacologic effects
Receptors
measurable to its pharmacologic effects
Dose
Drugs are _______ in choosing a drug molecule to bind to avoid constant activation or inhibition by promiscuous binding of many different molecules
Selective
Drugs have _______ binding and _________ with receptors
Selective binding and specificity
Changes its function upon binding in such a way that the function of the biologic system is altered in order to have pharmacologic effect
Receptors
Receptors are ___________ in ligand binding characteristics (respond to proper chemical signals and not to meaningless ones)
selective
Mediate the actions of both pharmacologic agonists and antagonists
Receptors
Most receptors are ______ which provide the necessary diversity and specificity of shape and electrical charge
proteins
Specific binding region of the macromolecule
Receptor Site or Recognition Site
happens to the drug when there is an interaction between the drug and the receptor
initiates the action of the drug
Receptor sites have _______ and _______ affinity to the drug molecule.
High and selective affinity
T/F Even if the drug enters the body, but it cannot reach the target receptor, it will still take effect
F; it will not take effect
Classification of Receptors
Best characterized drug receptors
Regulatory Proteins
Classification of Receptors
Mediates the action of endogenous chemical signals like neurotransmitters, autacoids, and hormones
Regulatory Proteins
Classification of Receptors
Mediates the effects of the most useful therapeutic agents as it takes effect immediately
Regulatory Proteins
Classification of Receptors
Inhibited (or less commonly, activated) by binding a drug
Enzymes
Classification of Receptors
Na+/K+ ATPase Pump, the membrane
receptor for digitalis
Transport Proteins
Classification of Receptors
Stabilizes Tubulin
Structural Proteins
Molecules that translate the drug-receptor interaction into a change in cellular activity
Effectors
T/F Some receptors are also effectors
True
Signaling Mechanism
________ drug that crosses the plasma membrane and acts on intracellular receptors
Lipid-soluble
T/F A single molecule may incorporate both the drug binding
site and the effector mechanism
True
Signaling Mechanism
Steroids
Lipid-soluble drugs
Signaling Mechanism
Where steroid attaches to alter genetic transcription
hsp90
Signaling Mechanism
Transmembrane receptor protein-intracellular enzymatic activity is regulated by a _________ that binds to the proteins’ extracellular domain
ligand
Signaling Mechanism
Transmembrane Receptors that binds and stimulates a ____________
Tyrosine kinase
Signaling Mechanism
Other term for Protein Tyrosine Kinase Associated receptors
JAK - Janus Kinase
Signaling Mechanism
Type of receptor that causes dimerization
Transmembrane receptors that stimulates protein tyrosine kinase
Signaling Mechanism
Insulin
Transmembrane receptors that bind and stimulates protein tyrosine kinase
Signaling Mechanism
_______________ transmembrane ion channel: which regulates the opening of the ion channel
Ligand-gated
Signaling Mechanism
causes drug to mimic or block the
action of agonists
ligand-gated ion channels
Signaling Mechanism
Type of receptor that is similar to our neurotransmitter receptors
Ligand-gated transmembrane ion channel
Signaling Mechanism
GABA, excitatory acetylcholine
ligand-gated transmembrane ion channel
Signaling Mechanism
Receptors transmit its signal across the plasma membrane by (increasing/decreasing) transmembrane conductance of the relevant ion
Increasing transmembrane conductance
Signaling Mechanism
Binding site of Acetylcholine outside to allow opening of a central aqueous transmembrane ion channel where sodium enters
α biding sites
Signaling Mechanism
Catecholamine / epinephrine
Transmembrane receptor coupled with G protein
Signaling mechanism
Increasing the intracellular concentrations of second messengers
Transmembrane receptor coupled with G protein
modulate the production of intracellular messengers
G protein
Type of G protein
↑ Adenylyl cyclase → ↑ cAMP
Gs, Golf
Type of G protein
Receptor for
- β-Adrenergic amines
- Histamine
- Serotonin
- Glucagon
- Many other hormones
Gs
Type of G protein
↓ Adenylyl cyclase → ↓ cAMP
Gi1, Gi2, Gi3
Type of G protein
Open cardiac K+ channels → ↓ heart rate
Gi1, Gi2, Gi3
Type of G protein
receptor for
- α2-Adrenergic amines
- Acetylcholine (muscarinic)
- Opioids Serotonin
- Many others
Gi1, Gi2, Gi3
Type of G protein
Receptor for Odorants (olfactory epithelium)
Golf
Type of G protein
Receptors for Neurotransmitters in brain (not yet specifically identified)
Go
Type of G protein
↑ Phospholipase C → ↑ IP3, diacylglycerol, cytoplasmic Ca2+
Gq
Type of G protein
Receptors for
- Acetylcholine (muscarinic)
- Bombesin
- Serotonin (5-HT2)
- Many others
Gq
Type of G protein
Receptors for Photons (rhodopsin and color opsins in retinal rod and cone cells)
Gt1, Gt2
Type of G protein
↑ cGMP phosphodiesterase → ↓ cGMP (phototransduction)
Gt1, Gt2
Intracellular Second Messengers
Mediates hormonal responses
cAMP (Cyclic adenosine monophosphate)
Intracellular Second Messengers
cAMP mobilizes stored energy (breakdown of carbohydrates in the liver stimulated by _____________
catecholamines
cAMP
Conservation of water by the kidneys mediated by ___________
vasopressin
cAMP
Calcium homeostasis
Parathyroid hormone
cAMP
Heart rate and contraction by
beta-adrenomimetic catecholamines
T/F cAMP is a product of the enzyme adenylyl cyclase and it converts ATP to cAMP
T
stop the effect of your cAMP
Phosphatase
Intracellular Second Messengers
Bind to receptors linked to G proteins while other bind to receptor tyrosine kinases
Calcium and Phosphoinositides
Intracellular Second Messengers
Calcium and Phosphoinositides stimulates the membrane enzyme __________
phospholipase C
Intracellular Second Messengers
phospholipase C cleaves PIP2 into
diacylglycerol (DAG) and Inositol Triphosphate (IP3)
Calcium and Phosphoinositides
release the Calcium (Ca2+)
Inositol Triphosphate (IP3)
Intracellular Second Messengers
Few signaling roles in a few cell types like the intestinal mucosa and vascular smooth muscle cells
cGMP (Cyclic guanosine monophosphate)
Intracellular Second Messengers
Causes Relaxation of vascular smooth muscles by a kinase-mediated mechanism
cGMP (Cyclic guanosine monophosphate)