02 - Drug receptor interactions (pharmacodynamics) Flashcards
(42 cards)
Agonists…
activate receptors!
Antagonists…
block the action of an agonist
Benzodiazepines bind to the ( allosteric / orthosteric ) site of ( GABA A / GABA B / alpha-andrenergic) receptors
Allosteric site of GABA A
Benzodiazepines enhance the endogenous…
Effect of GABA (leading to greater hyperpolarisation, as more Cl- passes through the ion channel)
NSAIDs work by…
Enzyme inhibition
NSAIDs inhibit…
Cyclooxegenase
Drugs that mimic the endogenous process at a receptor are acting as…
Agonists
Drugs that inhibit the endogenous process at a receptor are acting as..
Antagonists
Histamine receptors have at least…
14 subtypes
Receptor subtypes may have both different specificities for agonists and differences in the…
Signal transduction pathway
The 4 major types of receptor are…
- Ligand-gated ion channel receptors
- G-Protein coupled receptors
- Enzyme (kinase) linked receptors
- Intracellular receptors
Which type of receptor acts the fastest?
Ligand-gated ion channel receptors (ionotropic)
All ionotropic channels have ( intracellular / extracellular ) ligand binding sites
Extracellular
G-Protein coupled receptors are slower than ligand-gated ion channel receptors, but have a…
Greater variety of responses
G-Protein coupled receptors are the most common…
Receptor type and drug target
G-Protein coupled receptors can either be (2)…
Direct (linked with an enzyme) or Indirect (triggers an ion channel)
adrenoreceptors are…
G-protein coupled receptors
Salbutamol is a drug which mimics the endogenous effects of which neurotransmitter on which receptors?
Epinephrine, (beta-2) andrenoreceptors
A trimeric G-protein is comprised of 3 subunits…
- alpha
- beta
- gamma
Which G-protein subunit has the most significant catalytic activity?
Alpha (which binds GTP)
Name the 3 main subtypes of alpha-subunit….
- Gs (activates adenyl cyclase, Ca2+ channels)
- Gi (inhibits adenyl cyclase, activates K+ channels)
- Gq (activates phospholipase C)
alpha 1 adrenoreceptor activates a G-protein with which alpha subunit type?
Gq -> activates phospholipase C
alpha 2 adrenoreceptor activates a G-protein with which alpha subunit type?
Gi -> inhibits adenyl cyclase and activates K+ channels
beta 1 and 2 adrenoreceptors activate a G-protein with which alpha subunit type?
Gs -> stimulates adenyl cyclase and activates Ca2+ channels
