抄録
Sarcalumenin (SAR), a Ca2+-binding protein located in the longitudinal sarcoplasmic reticulum (SR) of striated muscle cells, interacts with sarcoplasmic reticulum (SR) Ca2+-ATPase protein (SERCA2a). Since aging is associated with a decrease in SERCA2a activity that causes cardiac dysfunction and impaired exercise capacity, SAR may play a role in the impairment. To test the hypothesis, we herein examined cardiac function by using a high-fidelity pressure transducer and exercise performance by treadmill test in aging SAR-deficient mice. As previously demonstrated in senescent human and animals, cardiac function and exercise performance were decreased in both senescent wild-type and SAR-deficient mice (over 18-month old) when compared with young adult mice (2-4-month old). However, the declines were much greater in senescent SAR-deficient mice. Our data demonstrated that systemic ablation of SAR caused a significant reduction in cardiac function and exercise ability in aging animals, indicating that SAR plays an important roles in preventing the age-related decline in striated muscle performance. [J Physiol Sci. 2007;57 Suppl:S196]
