Lecture 3 and 4 Flashcards
What is an agonist?
Molecule that binds to the target – generate a response / activation
What is an Antagonist?
Molecule that binds to target – does not generate a response
What is Affinity?
A measure of the binding constant of the drug for the receptor protein
What is Efficacy?
A measure of the ability of the drug to activate the receptor and it’s corresponding signalling system
What are naturally occurring ligands?
Neurotransmitters and hormones
What is a Partial Agonist?
Does not obtain max efficacy
What is Full Agonist?
Obtains max efficacy
What are α- adrenoreceptor agonists?
G-Protein coupled receptors
Is Phenylphrine a full agonist?
Yes
What type of agonist is Tolazine?
Partial agonist
What happens when Partial agonsits are in the presence of a full agonist?
Act as an antagonist due to competition
What drugs are partial agonist?
Salbutamol
Purpose of Salbutamol?
Regulation of response of receptors to endogenous ligand
What is the function of competitiv antagonist?
Competes with agonists for receptors
What are the functions of irreversible antagonists?
BInd to receptor permanently or dissoicates slowly
Drugs that desensitiation can occur?
Opioids, alcohol, dopaminergic drugs
What is Pharamcodynamic tolerance?
Down regulation of opioid receptors as they are repeatdly flooded
Where are Ligand gated ion channels found?
Heart and Neuromuscular junction
Examples of Ligand-gated ion channels?
- Nicotinic cholinergic receptors- neuromuscular junctions
- GABA glutamate receptors – brain
Are are exmplaes of G-Protein coupled recepotrs?
muscarinic ACh receptor, adrenoreceptors, dopamine receptors, serotonin receptors as well as many orphan receptors
What is the structure of G-Protein-coupled receptors?
General Heptahelical structure
What are the two main secondary messenger systems that G-Protein coupled receptors activate?
- Adenylyl cyclase/cAMP
- Phospholipase C/inositol trisphosphate (IP3 )/diacylglycerol (DAG):
What is the PNS divided into?
- autonomic nervous system which controls automatic functioning like breathing and heart rate
- somatic nervous system, involved in voluntary movement
- Enteric nervous system – local control – GI tract, pancreas, gallbladder
What are Astrocytes?
Most abundant and versatile
- Support and brace neurons, anchor them to their blood supply
