Metabolic behavior of alpha-ray activity in large human arteries: relationship to atherosclerosis.

The paradoxic biologic behavior of tissue calcium metabolism is emphasized. Although calcium salts are essential for the development of bones, they also contribute to aging of the large human arteries. The heavy elements providing alpha-ray activity tend to be metabolized like calcium. The concept of an osteoporosis-atherosclerosis relationship led to a series of investigations in which ash content and alpha-ray activity were examined in abdominal aortas, coronary arteries, pulmonary arteries and, for comparison, in bones and ventral costal cartilages. Both ash content and alpha-ray activity rise with age in the aorta and in the coronary arteries, but there is no such increase in the pulmonary arteries. A statistically significant correlation between ash content and alpha-ray activity has been found only in aortas and coronary arteries. This correlation is even closer in the coronary arteries of subjects who die of coronary artery disease and in the aortas of the elderly. Wet tissue alpha-ray activity in an aorta with severe atherosclerosis may be 220 times higher than in an aorta without significant atherosclerosis. Alpha-activity in bones and in ventral costal cartilages tends to decline in advancing years, though in the cartilages the calcium deposits increase with age. Our studies reveal a close relationship between atherogenesis and the unique metabolic behavior of alpha-ray radiation in the large human arteries.