What is the role of kallikrein?
Kallikreins are responsible for the coordination of various physiological functions including blood pressure, semen liquefaction and skin desquamation.
What does the kinin system do?
Kinins are proteins in the blood that cause inflammation and affect blood pressure (especially low blood pressure). They also: Increase blood flow throughout the body. Make it easier for fluids to pass through small blood vessels.
How is kallikrein formed?
Kallikrein (PKa), generated by activation of its precursor prekallikrein (PK), plays a role in the contact activation phase of coagulation and functions in the kallikrein-kinin system to generate bradykinin.
How is the kinin system activated?
Activation of the kinin system commences when circulating complexes of plasma prekallikrein and high molecular weight kininogen (HK) bind to a receptor complex present on endothelial cells consisting of urokinase plasminogen activator receptor (uPAR), cytokeratin-1 (CK-1) and gC1q-receptor (gC1qR).
Is kallikrein a vasodilator?
These data indicate that renal hK1 or other related serine proteases might exert regulatory control on sodium excretion (i.e. limit sodium accumulation) in salt-replete hypertensive patients. Kallistatin, which binds to hK1 and inhibits its activity, unexpectedly acts as a potent vasodilator in rodents.
What receptor does kallikrein bind to?
Human bradykinin B(2) receptor is activated by kallikrein and other serine proteases. Mol Pharmacol. 2000 Oct;58(4):828-36. doi: 10.1124/mol.
What are Bradykinins and their function?
Bradykinin is a potent endothelium-dependent vasodilator and mild diuretic, which may cause a lowering of the blood pressure. It also causes contraction of non-vascular smooth muscle in the bronchus and gut, increases vascular permeability and is also involved in the mechanism of pain.
What do kinins cause?
Effects of Kinins Kinin are short lived peptides that cause pain sensation, arteriolar dilation, increase vascular permeability and cause contractions in smooth muscle.
What is kallikrein activation?
Activation of the plasma kallikrein system is initiated by the Hageman factor (coagulation factor XII), a single chain globulin (molecular weight 80,000), which can be activated by exposure to an activating macromolecular anionic surface and by endotoxin, as well as by an autocatalytic mechanism.
What is a plasma kallikrein inhibitor?
C1 inhibitor (also called C1 esterase inhibitor) is a serine protease inhibitor that normally prevents uncontrolled contact activation and bradykinin production by covalently binding to and inactivating plasma kallikrein.
What is Fletcher factor?
Prekallikrein (PK), also known as Fletcher factor, is an 85,000 Mr serine protease that complexes with high-molecular-weight kininogen. PK is the precursor of plasma kallikrein, which is a serine protease that activates kinins.
How does inflammation cause coagulation?
Inflammation initiates clotting, decreases the activity of natural anticoagulant mechanisms and impairs the fibrinolytic system. Inflammatory cytokines are the major mediators involved in coagulation activation. The natural anticoagulants function to dampen elevation of cytokine levels.