Ca2+ scraps: local depletions of free [Ca2+] in cardiac sarcoplasmic reticulum during contractions leave substantial Ca2+ reserve.

@article{Shannon2003Ca2SL,
  title={Ca2+ scraps: local depletions of free [Ca2+] in cardiac sarcoplasmic reticulum during contractions leave substantial Ca2+ reserve.},
  author={T Randolph Shannon and Tao Guo and Donald M. Bers},
  journal={Circulation research},
  year={2003},
  volume={93 1},
  pages={40-5}
}
Free [Ca2+] inside the sarcoplasmic reticulum ([Ca2+]SR) is difficult to measure yet critically important in controlling many cellular systems. In cardiac myocytes, [Ca2+]SR regulates cardiac contractility. We directly measure [Ca2+]SR in intact cardiac myocytes dynamically and quantitatively during beats, with high spatial resolution. Diastolic [Ca2+]SR (1 to 1.5 mmol/L) is only partially depleted (24% to 63%) during contraction. There is little temporal delay in the decline in [Ca2+]SR at… CONTINUE READING