FIGURE 9.

ATP-induced Ca²⁺ oscillations are inhibited by CytC but not by CT9 peptide. Experiments as in Fig. 8 but now performed with ATP as the oscillation-inducing stimulus. A, example traces of vehicle/CytC-loaded cells and their controls. B, CytC inhibited the oscillatory activity, and this effect was suppressed by co-loading with IP₃RCYT peptide. C, less Ca²⁺ was liberated from intracellular stores in the presence of CytC, indicating more complete store emptying; accordingly, mitochondrial Ca²⁺ uptake was larger. D, representative traces of vehicle/CT9-loaded cells. E, CT9 peptide had no effect on ATP-triggered oscillations. F, Xestospongin-C, U73122, and thapsigargin inhibited ATP-triggered oscillations. Significance symbols are as defined in Fig. 8.