Lecture 1-4 Flashcards
Pharmacodynamics
How drug acts on its target cells and the body
Pharmacokinetics
How your body does to the drug to get it to the target cells
Pharmacokinetics steps
ADME (Absorption, distribution, metabolism, elimination)
Bioavailability
amount of the drug that gets through the liver (varies between individuals)
Selectivity
describe whether a drug has a more specific effect or more generalized effect. (selective drugs vs non-specific)
Intracellular receptors
drugs able to cross the membrane into the cell and alter gene transcription/DNA and protein synthesis.
Agonists vs Antagonists
Agonists activate receptors
Antagonists take place and inhibit activation of the agonists.
V or F: Agonist and allosteric modulators are competitive.
False.
Major features of receptors:
- Quantitative relationship (affinity, concentration of drugs and number of receptor)
- Specificity ( stereoselectivity)
4 Major superfamilies
- Ligand-gated ion channels (LGICs)
- G protein-coupled receptors (GPCRs)
- Receptor tyrosine kinase (RTKs)
- Nuclear hormone receptors
LGICs receptor responsible for
Nb of Subunits:
Fast synaptic transmission (release an electrical effect on the postsynaptic neuron)
4-5 subunits
Nb of subunits on GPCRs
1 subunit composed of 7 transmembrane spanning domains.
GPCRs function
- Binding of the ligand to the stimulatory receptor
- GPCRs activate signals by inducing a conformation change. (exchange GTP for GDP)
- alpha is active
- G subunits dissociate with active alpha activating the the effector.
- Lead to the second messager.
inhibitory receptor on GPCRs cause
GDP-GTP exchange on the alpha subunit. Which inhibits the 2nd messager.
RTKs structure
extracellular ligand binding domains
one transmembrane spanning segment
intracellular tyrosine kinase domain.
RTKs function
- Binding of a ligand to the extracellular domain.
- It cause dimerization of the receptor
- stimulates a tyrosine kinase activity within the intracellular domain.
Nuclear hormone receptors located
cytosol
autocoid
biological factors which act like hormones with brief duration.
Ion Channels 2 major types
- Voltage-gated
2. Receptor-operated
Autocrine
acting back on the same cell
Endocrine
moving through the circulation
Paracrine
acting on neighboring cells
Juxtacrine
one cell contacts another
T or F: Two G-protein coupled receptors cannot exist on the same cell and have opposite effects.
False. It can have opposite effects; activate and inhibit a particular enzyme
Receptor turnover
cells continually making new receptors and recycling old ones.
T or F: Microtubules and other fibers that undergo mitosis are a site for drug action.
True. Anticancer drugs act on it, target rapidly dividing cells to prevent cells from dividing properly.
Magnitude of drug effect study with
- Dose response curve. (threshold and ceiling dose and ED50)
- Receptor occupancy