Figure 4.

Reciprocal actions of CCCP on mitochondrial and cytosolic Ca²⁺. Fluorescence signals from rhod-2 and Calcium Green, coloaded as AM esters in a preliminary incubation, were recorded simultaneously from a single cell, beginning 3–5 min after the perforated patch clamp configuration was established. The perfusion medium then was supplemented with 10 mM Ca²⁺ and 3 μM oligomycin and then with 2 μM CCCP as indicated. At the arrows 500-ms depolarizations were applied. A postexperimental calibration procedure (see Materials and Methods) provided parameters for conversion of rhod-2 and Calcium Green fluorescence to the indicated mitochondrial and cytosolic free Ca²⁺ concentrations (Ca_m and Ca_c, respectively). The results shown are representative of four similar experiments. (Insets) The initial portions of Ca_m and Ca_c responses are aligned in time to the depolarizing stimulus.