Pharmacology Flashcards
How does intercellular communication occur
Chemical signals released from cell produces a response only in cells with specific receptor
Different receptors for same chemical signal= different responses
What molecules bond to intracellular receptors
Lipid soluble molecules
Dissolve through lipid bilayer
Bind to intracellular receptors in nucleus/cytosol
What are some examples of intracellular receptors
NO (Nitric oxide)
Steroid hormones
What molecules bind to cell surface receptors
Hydrophilic molecules
What are the different types of cell surface receptor
Receptor channels - ionotropic
G protein coupled receptors - metabotropic
Receptor-enzymes
Integrin receptors
What happens when G protein coupled receptors bound to andenylyl cyclase
Produces cAMP as 2nd messenger
Regulates protein kinase A activity
Phosphorylates target proteins changing activity
What happens when G-protein coupled receptor bound to Phospholipase C
Produces IP3 and DAG as 2nd messengers
Releases Ca2+
Regulates protein kinase C activity
Phosphorylates as well
What are the sources of Ca 2+ as second messenger
Internal stores - IP3 or Ca2+ from endoplasmic reticulum
Via gated channels
Inhibition of Ca2+ transport out of cell
What are the effects of Ca2+
Directly affects target protein
Binds to calmodulin-> activates target protein
Works via other Ca2+ binding protein
How do drugs interact
Via binding to a receptor
What enables a maximum response from a drug
Number of drugs binding to their receptors
What is affinity determined by
Strength of chemical attraction between drug and receptor
What are the affinities and efficacies of agonists, partial agonist and antagonist
What is a drug?
Any chemical agent that affects a biological system
What are some examples of receptors?
Cell surface receptors
Intracellular receptors
Ion channels
Carriers
Enzymes
Nucleic acids
