Matrix volume effects on heart mitochondrial respiration and calcium retention capacity (CRC). Heart mitochondrial matrix volume was modulated by changing the osmolarity of the buffer using different concentrations of KCl. The KCl concentrations and the respective approximate medium osmolarities are depicted on the x-axis. The standard incubation medium, 125 mM KCl, is marked by vertical dashed line (A) Changes in matrix volume were monitored by assaying changes in light absorbance at 520 nm (∆ABS). (B) Respiration rates at state 3 (during ADP phosphorylation) and state 4 (after ADP was converted to ATP) are demonstrated. (C) Calculations of mitochondrial CRC at the different buffer osmolarities. Values are means ± S.E.M. * indicates p < 0.05 compared to control (125 mM KCl).
Morota et al. BMC Cell Biology 2013 14:40 doi:10.1186/1471-2121-14-40