The Aging Microvasculature and Alzheimer ' s Disease

The microvasculature of the body diminishes with age, and this is thought to be a major contributing factor in the progression of age-related loss of organ function, particularly in energy-hungry tissues such as muscles and the brain. Every tissue is densely packed with tiny blood vessels, hundreds of capillaries passing through every square millimeter in cross-section. This small-scale microvasculature is needed in order to efficiently deliver sufficient nutrients to all cells in a tissue. Absent capillaries, perfusion of nutrients is only useful over a very short distance indeed, and its effectiveness declines quickly as that limit is approached. Unfortunately, the density of capillary networks is lost with age. The mechanisms regulating angiogenesis, the growth and maintenance of blood vessels, are very complex, but also quite well explored as a result of their relevance to many areas of medicine. Some approaches are demonstrated to produce usefully greater regrowth of blood vessels following injury in animal studies, such as mobilization of hematopoietic cells from the bone marrow. Many of the possible points of intervention via upregulation or interdiction of a single protein result in problematic growth, however. Blood vessels grow where they should not grow, or are poorly formed, or both. Excessive angiogenesis of leaky vessels in the eye, provoked by pro-growth signals secreted by senescent cells, is a feature of macular degeneration, for example. Noneth...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs