Pharmacology Flashcards
Name 3 appropriate response receptors can produce
- membrane permeability
- metabolism
- secretory activity
Give two examples of lipid soluble molecules which bind to intracellular receptors
- Steroid hormones
- NO (generates cGMP > regulates cell actvity)
When a signalling molecule can penetrate the cell to bind tot an intracellular receptor, what do they bind to
Plasma Receptors
What is an ionotropic receptor?
This is a receptor which also act as an ion channel. Contains fast IPSPs and EPSPs.
What is the function of receptor tyrosine kinases ?
proliferation & differentiation
What are process do receptors that interact with JAK kinases perform?
protein synthesis
What is the biggest group of receptors
Those which interact with the G protein
In G-protien receptors what does cAMP regulate?
It tends to regulate the activity of an enzyme
What is a tried and trusted way of regulating the activity/function of protiens?
Once enzyme is activated phosphorylation occurs and as a result, we can determine what role it is playing i.e. secretion, metabolism, transport or whatever
G protiens are coupled to adenylyl cyclase, this causes:
produces cAMP that regulates PKA
G protiens are coupled to Phosphoplipase C, this causes:
produces DAG that regulates PKC
What does PKA and PKC do ?
phosphorylate, and therefore regulate, a whole host of cell proteins (enzymes, channels, etc)
What is a drug?
any chemical agent that affects a biological system
How does a drug interact?
By binding to a specific site - i.e. a RECEPTOR
How does drug dosage and response relate
Directly proportional higher drug (ligand) conc. higher response until….
When all receptors are bound to drug, what is the response called?
Maximum (saturated) response
What is affinity?
strength of chemical attraction between drug and receptor - low EC50 indicates high affinity
What is an EC50 value?
half maximal response, presumably because half the availabel receptors are activated – quanitifies affinity
What is efficacy of a drug?
Efficacy is determined by how good the drug is at activating the receptor
Hence what does the size of the response depend on ?
Drug affinity + efficacy
