July 3, 2013
Tick Saliva Sheds New Light On Blood Clotting
Rebekah Eliason for redOrbit.com - Your Universe Online
Scientists recently uncovered a surprising potential connection between tick saliva and treatment for heart disease and stroke. Ixodes ticks, commonly known as deer ticks or blacklegged ticks, contain a specific protein in their spit that links to treatment for these diseases. These ticks have also long been known as transmitters of a variety of diseases, including Lyme disease.Deer ticks burrow into the skin of their host and then remain there to feast on their blood. During this process the ticks damage small blood vessels, which would normally prompt the body's blood clotting mechanism.
Effective blood clotting was a vital process in the evolutionary development of humans because it stops a wound from continuing to bleed. However, at times clotting occurs when it should not and can trigger a heart attack or stroke.
Along with sucking blood and damaging minor blood vessels, ticks also inject small amounts of their saliva into their host organism. That saliva contains a protein that blocks the body's complex natural clotting cascade in a similar way to how blood thinners interact with the coagulation process.
Tick saliva was found to block the activation of two specific clotting factors known as factor X and factor V. However, the inhibition of clotting is only temporary, as factors X and V work jointly to activate a third clotting factor that eventually overcomes the effects of the tick spit and reactivates clotting.
Through the study of tick saliva, scientists were able to more fully understand the process of blood clotting. Coagulation factors were already known for the activation of factor V, but the vital role of factor X in activation is now better understood.
As a result of studying tick saliva's role in clotting, a new model for blood coagulation has been formed that leads to improved understanding of this complicated natural defense process. This could lead to new development for anti-clotting drugs that aid in the treatment of stroke and heart disease.