Drugs & Receptors Flashcards
Name some drug targets
ion channels, enzymes, carriers
What drugs target ion channels
lignocaine, apamin, nifedipine
What does lignocaine bind to
voltage gated sodium channels
What is the effect of lignocaine
stops action potential firing, stops transmission of pain
What does apamin effect
potassium channels
What do dihydropyridines target
voltage gated calcium channels - heart
What do dihydropyridines treat
high BP
Name an ACE inhibitor
captopril
What does captopril treat
low BP
What does aspirin inhibit
COX enzyme
What drugs target enzymes?
aspirin, pargyline, captopril
What are pargyline and clorgyline
anti-depressants
What does pargyline inhibit
enzyme MAO-B
What is the effect of pargyline
prevents neurotransmitters being broken down
What drug binds to sodium potassium ATPase
digoxin
What does digoxin treat
heart failure
What is fluoxetine
anti-depressant
What is the effect of fluoxetine
binds and inhibits serotonin transporter
What is the effect of agonist binding to ligand gated ion channels
channels open
What is usually the agonist for ligand gated ion channels
ACh
How many times do GPCRs span the membrane
7 times
Describe the structure of kinase linked receptors
single transmembrane domain, enzyme built in
Where are nuclear receptors foudn
inside the cell
What is the function of nuclear receptors
regulate gene transcription
Describe the structure of nuclear receptors
DNA linked, has zinc fingers
Describe the ligand requirement for nuclear receptors
must be able to cross PM
Which receptors are ionotropic
ligand gated ion channels
How many subunits do ligand gated ion channels have
3-5
Describe the structure of ligand gated ion channels
complex arranged to form a central aqueous pore
What is the effect of agonist binding to ligand gated ion channels
opening
describe the synaptic transmission of ligand gated ion channels
fast
What ionotropic receptors are positive
acetylcholine, nicotinic, 5HT3
What are positive ionotropic receptors selective for
cations
What are negative ionotropic receptors selective for
anions
Which ionotropic receptor has 4 transmembrane domains
nicotinic
Describe acetylcholine ionotropic receptors
excitatory, cause depolarisation
Describe the structure of nicotinic receptors
pentameric structure, heteromeric assembly,
How do nicotinic channels open
two ACh molecules bind
What do ACh molecules bind to on nicotinic channels
interfaces between alpha subunits
what is the agonist for neuromuscular junction brain
nicotine
What is the antagonist for neuromuscular brain junction
tubocurarine
What does activation of ionotropic receptors for inhibitory neurotransmitters do
inhibits membrane depolarisation, reduces AP firing
What is the antagonist of GABA
picrotoxin
How many subunits do GPCRs ahve
3
What are the subunits of GPCRs
alpha, beta, gamma
What are the endogenous ligands for GPCRs
hormones, neuropeptides, small molecule transmitters
What are the functions of GPCRs
transduce signals and bind guanine nucleotides
Describe GPCRs at rest
GDP - inactivated, bound
Describe GPCRs when activated
GTP
What is the effect of an agonist binding to a G-Protein
activates G-protein, induces exchange of GDP - GTP
Describe the structural changes of an activated G-Protein
protein dissociates into alpha and beta subunits
What effectors are regulated by GPCRs
enzymes, ion channels
What is cAMP
2nd messenger, small molecule
