The Adrenergic System and Stem Cell-Mediated Myocardial Repair
The continuous increase of average human life span is yielding a progressively older population pool. With the aging population and increasingly sedentary lifestyle, chronic cardiovascular diseases are approaching epidemic proportions in nearly all developed countries. Decline in cardiovascular performance is counteracted by the interaction of the sympathetic (adrenergic) nervous system (ANS) and the parasympathetic system. Acutely, the elevated activity of the adrenergic system will swiftly reestablish cardiac function and return to steady levels. However, a chronic manifestation of altered cardiac function is followed by prolonged and compensatory ANS hyperactivity, which over time will lead to increased pressure on the already weakened heart. Thus far, β-receptor blockade has been the main therapeutic approach with which the inhibition of the adrenergic drive has had a positive effect counteracting the progression of cardiovascular decline. With the emergence of new discoveries in stem cell research and their possible contribution to cardiac cell turnover and tissue repair, it is critical to evaluate the extent of the impact of the ANS on cardiac regeneration via the regulation of stem cells.
