Telomere attrition of the human abdominal aorta: relationships with age and atherosclerosis.

Little is known about the turnover rate (i.e. the rate of replication and death) of cells in the intima and media of human arteries as a function of age and atherosclerosis. One indicator of the replicative history of cells is telomere length. In this work we explored the rate of telomere attrition as a function of age and atherosclerosis in cells of the human abdominal aorta. Telomere length, measured by the terminal restriction fragment using Southern analysis, was determined in the intima and media of the distal (infrarenal) versus proximal (suprarenal) segments of the abdominal aorta. Telomere length was then correlated with age and atherosclerotic grade. The rate of age-dependent telomere attrition was higher in both the intima and media of the distal versus proximal abdominal aorta. In addition, telomere length was negatively correlated with atherosclerotic grade. However, after adjustment for age, this relationship was not statistically significant. The high rate of age-dependent telomere attrition in the distal abdominal aorta probably reflects enhanced cellular turnover rate due to local factors such as an increase in shear wall stress in this vascular segment.