Essential Pharmacology Flashcards
Can the same receptor on a cell be coupled to different responses?
Yes
What should the ligand be in order to bind to an intracellular receptor?
Hydrophobic/lipid soluble
Give an example of a ligand that is lipid soluble…
Steroid hormones
What do intracellular receptors often regulate?
Rate of transcription, often known as transcription factors
What are the 4 types of plasma receptors?
- Ones with ion channels (ionotropic) - ligand gated channels
- Receptors that act and enzymes
- Receptors that regulate enzymes
- G protein coupled
So what is the point of receptors?
They enable the specificity of the action of different transmitters and hormones
What is the largest class of plasma receptors?
G protein coupled
What happens when a G-protein receptor is coupled to adenylyl cyclase
It increases cAMP which activates PKA (if unbound will do the opposite)
What happens when a G-protein receptor is couples to Phospholipase C?
Produces DAG which activates PKC
AND
IP3 which releases Ca2+ ions
What are PKA and PKC used for?
For phosphorylation - therefore regulate a host of cell proteins
How do drugs act?
By interacting with a binding site - a receptor
What happens the more drugs that bind to the receptors?
There is a bigger response until all of the receptors are filled and then increasing drug level doesn’t do anything…
What is efficacy?
Determines how good a drug is at activating a receptor - drugs can partially activate receptors
What is affinity?
How well the drug binds to the receptor
What is the affinity and efficacy of a full agonist?
High affinity
High efficacy
