3rd semester 2nd MT Flashcards
Which protease are responsible for the destruction of the intrinsic tenase and the prothrombinase complexes?
Thrombin
Protein C
Which protein co factors are responsible for the destruction of the intrinsic tenase and the prothrombinase complexes?
Thrombomodulin
Pritein S
Throughput of K+ ch
1-2x10^8
What carries the most info on the memb. Topology of an ion ch?
Hydropathy plot
Streptokinase mechanism
Human plasminogen in a complex with streptokinase becomes a plasminogen activator
What is the mode of antifibrinolytic action of TAFIa?
Cleaves C terminal Lys residues -> decreases the binding site for the tPA and plasminogen in fibrin and moderates the cofactor function of fibrin in plasminogen activation
Coumarin effect, in what drug is it present?
Warfarin
Decreases blood clotting by blocking an enzyme called vitamin K epoxide reductase that reactivates vitamin K
When do Ca ch. permits Na entrance?
When Ca conc is decreased
How does thrombin activates platelets?
Hydrolysis of memb. Proteins
Increasing cytosolic Ca conc.
tPA job?
Protein involved in the breakdown of blood clots
Catalyzes plasminogen -> plasmin
K+ ch structure
Tetramer
What stabilizes fVIII?
vWf
What is the role of TXA2 and what cell produces it?
Pro thrombotic effect
Produced by activated platelets
Structure of ATP sens. K+ ch
Octamer
4 kir6.2
4 SUR
Thrombaxane is inhibited by
Aspirin
NO will lead to?
Vasodilation
Increased blood flow
2 functions of vWf?
Carrier of fVIII
Mediator of platelet adhesion at high shear
Synthesis of NO starts from?
Arg
What activates protein C?
Thrombomodulin bound thrombin
What is the mode of activation of streptokinase?
Forms a complex with human plasminogen in which plasminogen gains activity as plasminogen activator
How does thrombomodulin modify blood coagulation?
Accelerates protein C activation by thrombin
What stimulates tPA?
Fibrin
Hemophilia B is caused by deficiency in?
fIX
Anti-phospholipid syndrome can be treated with (2)
Vit K antagonist
Heparin
What is the background of activated protein C resistance?
Arg 506 in fV is mutated
What can be a substrate for thrombin?
Fibrinogen V VIII XI XIII Platelets
Because_________ is inhibited by Aspirin, there is no production of _______ and _________
COX
TXA2
PGI2
What will deficiency in vit K leads to?
Reduces protein C levels
Reduces prothrombin levels
Actions of Heparin?
Facilitates thrombin inactivation by antithrombin
Where is the pore loop located?
Extracellularly
Effect of Sulfonylurea on ATP sensitive K channels, where do they bind?
Inhibit the ch -> depol -> insulin secretion
Binds SUR1
Ion ch are stochastic or deterministic?
Stochastic
How is fibrinolysis terminate?
a2 plasmin inhibitor inactivates plasmin
How can tPA activity increase?
In the presence of fibrin
List 3 plasminogen activators used in therapy?
tPA
uPA
Streptokinase
3 phases of platelets activation:
- Adhesion
- Activation
- Aggregation
Antithrombotic effects of thrombin?
Thrombin-TM complex activates protein C which will inhibit fV and fVIII
Substrates for factor VIIa?
fX
fIX
Structural consequence of coumarine?
Inhibition of Gla domain formation
ecto ATPase activity?
Inhibition of platelets activation
What are the vit K dependent factors?
II
VII
IX
X
What is TAFI (Thrombin Activatable Fibrinolysis Inhibitor)
Carboxypeptidase
What activates TAFI?
Thrombin-TM complex
TAFI action?
Reduces fibrinolysis by removing the C terminal residues that are important for the binding and activation of plasmin
hirudin action?
inhibits thrombin directly
how can the activity of tPA be increased?
in the presence of fibrin
location of CFRT?
apical side of endothelial cells
describe each hemophilia
A
B
C
A- fVIII
B- fIX
C- XI
what is the most frequent cause of hemophilia?
Antiphospholipid syndrome
where can we find Gla-domain?
II VII IX X protein C, Z, S
when will we give hirudin?
when a persim lacks antithrombin
what factor inhibits plasmin and how?
fXIIIa
makes Gln-Lys isopeptide bonds btw a2-antiplasmin and plasmin
