Changes In Contractile Proteins

Changes in muscle protein synthesis and turnover could account for at least part of the loss of muscle mass and strength during aging. Although studies have suggested that there are no changes in overall muscle synthesis, there seem to be selective changes in specific muscle proteins (Greenlund and Nair, 2003; Volpi et al., 2004). For example, the rates of myosin heavy chain isoform (MHC) Ila and Ilx synthesis have been shown to decrease in older subjects, which is a change probably due to a decline in mRNA levels (Greenlund and Nair, 2003). The exact cause of this change is unknown but could reflect the loss of type II muscle fibers during aging (Lexell, 1995). Furthermore, proteomic studies have demonstrated declines in myosin light chain and actin protein levels (Piec et al., 2005). There is also a decline in protein turnover in aging muscle due to declines in proteasome function that leads to the accumulation of proteins with damage such as oxidation. These damaged proteins may show impaired contractile function.

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Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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