The roles of satellite cells and hematopoietic stem cells in impaired regeneration of skeletal muscle in old rats.

Sarcopenia is the involuntary loss of skeletal muscle mass and strength that occurs with aging, resulting in physical frailty. One potential explanation for sarcopenia is the failure of muscle to regenerate after damage, some of which may be due to changes in the function of satellite cells. Recent studies have identified novel populations of adult stem cells in skeletal muscle, such as hematopoietic stem cells. To understand the cellular mechanisms of sarcopenia, we examined the expression of satellite cells and hematopoietic stem cells in old regenerating muscles based on the expression profiles of several markers related to those cells.