Platelet Aggregation

Thrombus formation is important in cardiovascular diseases.3334 Platelets are blood cell fragments that originate from the cytoplasm of megakaryocytes in the bone marrow and circulate in blood. They play a major role in the hemostatic process and in thrombus formation after an endothelial injury. Circulating human platelets also play an important role in the development of atherosclerosis, and increased platelet aggregation is associated with enhanced atherogenicity.35 Recent studies have provided insight into platelet functions in inflammation and atherosclerosis.36 Platelets release several growth factors and bioactive agents that play a central role in the development of thrombus and intimal thickening.37 A range of molecules, present on the platelet surface or stored in platelet granules, contribute to the crosstalk among platelets and other inflammatory cells during vascular inflammation, which is involved in the development and progression of atherosclerosis.38,39 Platelet activation can be seen indeed along the different phases of atherosclerosis. Most risk factors for atherosclerosis, including hypertension,40 cigarette smoking,41 diabetes,42 and hypercholesterolemia43,44 are able to increase the number of activated platelets in the circulation. An imbalance of the hemostatic system and persistent in vivo platelet activation can be observed in hypercholesterolemia and may have patho-physiological implications in the development and progression of the atherosclerotic plaques. Platelet activation influences the development of atherosclerosis, and inhibition of platelet thromboxane A2 (TX A2) production by aspirin45 indomethacin,46 or TX receptors by antagonist,47 dramatically diminish the formation of atherosclerotic lesions in LDL receptor and apolipoprotein E knockout mice. On the other hand, in the early phase of atherosclerosis, platelet activation may be attributed to reactive oxygen species (ROS) such as superoxide, hydroxyl radical, and peroxyni-trite, which are generated by some risk factors for atherosclerosis. Antioxidants decrease platelet aggregation.48-50 Vitamin E51-53 and polyphenols or polyphenol-rich nutrients were shown indeed to decrease platelet function in vitro and also ex vivo after supplementation to humans.54-59

Was this article helpful?

0 0
Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

Get My Free Ebook


Post a comment