Lecture 14 Purines Flashcards
Nuceloside
No phosphate
Adenosine
Nucleotide
Phosphate
ADP/ATP
Methylxanthines
Endogenous Purine
Ex. Caffeine
What are endogenous purines involved in
DNA/RNA synthesis
Energy Metabolism
Purinergic Signalling
What does Purinergic Signalling Regulate
Blood Flow
Platelet Aggregation
Neurotransmission
Immune Response
What are the three families of Purinergic Receptors
Adenosine Receptors (A1-3) - G-protein
P2Y (P2Y 1-14) - G-protein
P2X - ATP-gated cation channels
Which Adenosine Channels are G-Proteins
A1-3
P2Y
What Adenosine Receptors are not G-Protein
P2X
ATP-Gated cation Channels
Where is adenosine found
Cytosol of Cells (Intercell)
Body Fluids (Extracell)
Transported in and out of cells
Adenosine (Cardiovascular Effects)
Inhibits cardiac conduction (treats rapid heart rate)
Vasodilation
Inhibit Platelet Aggregation
Adenosine (CNS Effects)
Inhibits Neurons (Generally)
Caffeine CNS effect
Caffeine is an antagonist to Adenosine
Causes stimulating effect on neurons
Adenosine (Pro-Inflammatory Effects)
A1 Receptor
Promotes Mediator Release from Mast Cells
Increased Mucous Secretion in Lungs
Bronchoconstriction
Leukocyte Activation
Adenosine (Anti-Inflammatory Effects)
A2A Receptor
Theophyline
Blocks A1 Receptor to treat Asthma
Causes Bronchodilation
Inhibits Mucous Secretions
Where is ADP found
Stored in cell vesicles
When does ADP act
P2Y Receptor Signalling
What does ADP do
P2Y 12
Stimulates Platelet Aggregation
How do anti-platelet drugs work
Blocking ADPs actions
Destroying ADP
Blocking P2Y 13 Rece[tpr
Where does ATP primarily act
P2X receptors
How is ATP transported out from cell
Exocytosed / Released via channels
What does ATP do
Vasodilation
Stimulate Insulin Secretion
Neurotransmitter in periphery
Pain Transmission
Inflammation
How does ATP work in Vasodilation
Activates K+ channels to stimulate Vasodilation
How does ATP work in Inflammation
Is released from dead/dying cells
Stimulates neutrophils chemotaxis
