SACCM 164: Antiplatelet drugs Flashcards
Where is vWF stored?
in the Weibel-Palade bodies in the endothelium
in the alpha granules in platelets
What clotting factor initiates “tathering” of platelets?
vWF
What platelet receptor does vWF bind to?
Factor GP Ib-IX-V
Why are platelets and vWF more prominent in arterial thrombi?
because shear stress exposes the platelet binding site on vWF -> increaes vWF affinity to platelet GP Ib-IX-V
What platelet receptor does collagen bind to?
GP VI
What are the 2 names for the platelet receptor fibrinogen will bind to?
- integrin alpha IIb beta 3
- GP IIb/IIIa
What 3 changes do platelets undergo after being activated?
- shape change from discoid to ameboid shape with filopodia
- release of alpha and dense granule content
- cell membrane structural change –> phospholipid structure change
what complexes require the structural cell membrane change of activated platelets?
tenase and prothrombinase complexes need phospholids
what are the parts of the tenase complex?
- FIXa
- FVIIIa
- Ca2+
- Phospholipids
What are the parts of the prothrombinase compllex?
- FXa
- FVa
- Ca2+
- phospholipids
Name the 7 different molecule types present in the alpha granules of platelets
- adhesion molecules
- chemokines
- coagulation factors
- growth and angiogenic factors
- immunologic molecules
- other proteins
Name the 4 different molecule types present in the dense granules of platelets
- Ions
- Nucleotides
- Membrane proteins
- Transmitters
Name 6 different molecules stored in the alpha granules of platelets
- vWF
- fibrinogen
- FV
- FVIII
- plasminogen
- PAI-1
- IgG
- Albumin
Name 6 different molecules stored in the dense granules of platelets
- Ca
- ADP
- ATP
- serotonine
- epinephrine
- histamine
What platelet receptors does ADP work on?
P2Y1
P2Y12
What platelet receptors does thrombin work on?
PAR-1
PAR-4
What platelet receptor does TXA2 work on?
TP receptor
What platelet receptor does serotonine work on?
5-HT2A
What platelet receptor does epinephrine work on?
beta-2 receptors
Name 6 different substances that can activate platelets
- vWF
- ADP
- TXA2
- thrombin
- serotonin
- epinephrine
- collagen
What receptor does clopidogrel inhibit?
P2Y12 receptor on platelets
What is the different effect of P2Y1 versus P2Y12 receptor activation to platelets?
P2Y1 –> shape change and mild aggregation
P2Y12 –> integrin activation (GPIIb/IIIa!), granule content release, plays role in TXA2 production
What breed has been shown to carry a P2Y12 mutation?
Greater Swiss Mountain Dog
Name 2 other drugs than Clopidogrel from the family of Thienopyridines
- Ticlopride
- Prasugrel
