Declining Microcirculation as an Important Aspect of Aging

Tissues are supported by dense and intricate networks of capillaries, hundreds passing through any square millimeter cross-section. Many studies have shown that capillary density decreases with age, which is perhaps another of the many results of faltering tissue maintenance due to the decline in stem cell activity, or alternatively, a specific dysregulation of the processes of angiogenesis at the small scale, resulting from inappropriate cellular reactions to rising levels of damage and chronic inflammation. Fewer capillaries means a lesser delivery of nutrients and oxygen, and we might well wonder to what degree this contributes to atrophy and dysfunction in energy hungry tissues such as muscles and the brain. In this context, consider of the loss of muscle mass and strength that occurs with aging, known as sarcopenia. While sarcopenia is associated with a long, long list of potential contributing mechanisms, arguably the best evidence suggests that this loss of muscle capacity is caused by the declining activity of muscle stem cell populations. This connects well with a decline in capillary density, in that we can theorize either side as cause or consequence of the other. Another possible contributing factor is age-related mitochondrial dysfunction. Given that mitochondria are the power plants of the cell, responsible for transforming energy from nutrients into a form that cells can use, here too the possible connections to declining capillary density are obvious. ...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs