Info

Inhibitors

Inhibitor

Specificity

Antithrombin (AT) Alpha-2-macroglobulin

Tissue factor pathway inhibitor Heparin cofactor II Alpha-2 protease inhibitor CI inhibitor

Nonspecific

Xa, VIIa/TF complex

Antithrombin (AT) Alpha-2-macroglobulin

Tissue factor pathway inhibitor Heparin cofactor II Alpha-2 protease inhibitor CI inhibitor

Nonspecific

Xa, VIIa/TF complex

XIa, elastase XIIa, kaUikrem, XIa, CI (complement system)

Kinin System

Another plasma protein system in coagulation is the kinin system. This system is capable of vascular dilatation leading to hypotension, shock, and end-organ damage by its capability to increase vascular perma-bility.16 The kinins are peptides of 9 to 11 amino acids. The kinin system is activated by factor XII. Hageman factor XIIa converts prekallikrein (Fletcher factor) into kallikrein, and kallikrein converts kininogens into kinins. The most important is bradykinin (BK). This is an important factor in vascular permeability as well as a chemical mediator of pain. BK is capable of reproducing many characteristics of an inflammatory state such as changes in blood pressure, edema, and pain, resulting in vasodilation and increased microvessel permeability.13

Complement System

This system has a role in inflammation and the immune system as well as important thrombohemorrhagic disorders such as disseminated intravascular coagulation (DIC). Activated complement fragments have the capacity to bind and damage self tissues. Regulators of complement activation are expressed on cell surfaces. These protect the cell from the effects of cell-bound complement fragments. If this regulation process is abnormal, it may participate in the pathogenesis of autoimmune disease as well as inflammatory disorders. This system includes 22 serum proteins that play a role in mediating immune and allergic reactions and the lysis of cells due to a production of membrane attack complex (MAC). The lysis and disruption of red blood cells and platelets lead to the release of procoagulant material. This system is a sequential activation pathway. Complement is activated by plasmin through the cleavage of C3 into C3a and C3b. C3 causes increased vascular permeability, and because of the degranulation or lysis of mast cells, which in turn results in the release of histamine, C3b causes immune adherence.13

The interrelationship between the complement, kinin, and the coagulation system is complex and revealing. Coagulation and the elements that contribute to the success of the hemostatic system are multifactor-ial, and with each decade, more knowledge about this versatile system is learned. Figure 15.8 illustrates the important interrelationships between the coagulation, fibrinolytic, complement, and kinin systems.

Figure 15.8 Interrelationships between the coagulation, fibrinolytic, complement, and kinin systems.

Figure 15.8 Interrelationships between the coagulation, fibrinolytic, complement, and kinin systems.

The Prevention and Treatment of Headaches

The Prevention and Treatment of Headaches

Are Constant Headaches Making Your Life Stressful? Discover Proven Methods For Eliminating Even The Most Powerful Of Headaches, It’s Easier Than You Think… Stop Chronic Migraine Pain and Tension Headaches From Destroying Your Life… Proven steps anyone can take to overcome even the worst chronic head pain…

Get My Free Audio Book


Post a comment