The endothelial cells lining the blood vessels provide essential communication between the vessels themselves and circulating blood cells, allowing the blood to flow smoothly. In diseases such as atherosclerosis, however, the endothelial layer becomes damaged and the vessels do not function efficiently. Until recently, scientists believed that nearby endothelial cells were recruited to help repair damaged blood vessels or form new ones to circumvent blocked vessels or to repair wounds. Evidence now shows, however, that endothelial progenitor cells, probably generated in the bone marrow, circulate in the bloodstream and are recruited to form new blood vessels or repair damaged ones.
The NHLBI and Emory scientists postulated that endothelial cells generated in the bone marrow contribute to continuous repair of the endothelial lining of blood vessels and that a lack of these cells can lead to vascular dysfunction and the progression of cardiovascular disease. They measured the number of "colony-forming units," or clumps, of endothelial progenitor cells in the peripheral blood of 45 men with a mean age of approximately 50 years. The men had various degrees of cardiovascular risk, but no history of cardiovascular disease. The researchers also measured blood vessel function using non-invasive high-resolution ultrasound of the brachial artery.
The research team calculated the subjects' risk for cardiovascular disease using the Framingham risk factor score, commonly used to predict the risk of coronary artery disease in individ
Contact: Ron Sauder
Emory University Health Sciences Center