Fig 4.

Comparison of effects of exposure to paenilides and cereulides on the ΔΨ_m and oxygen consumption of mitochondria in glutamate-malate medium with KCl or NaCl. Mitochondria (1 mg protein ml⁻¹) were incubated in isotonic glutamate-malate medium with isotonic KCl or NaCl (pH 7.3), as described in the legend of Fig. 3. A TPP⁺-selective electrode was used to measure the ΔΨ_m. Oxygen consumption was measured by use of a Clark oxygen electrode. (A and B) Changes in the ΔΨ_m (A) and oxygen consumption (B) in response to added paenilides, at 4.5 ng ml⁻¹ (trace 2) and 9 ng ml⁻¹ (trace 3), in medium with KCl. Trace 1, vehicle only (methanol). (C and D) ΔΨ_m and oxygen consumption of mitochondria in medium with NaCl. Trace 1, vehicle only (methanol); trace 2, paenilides at 9 ng ml⁻¹. (E and F) Responses of ΔΨ_m and mitochondrial oxygen consumption to added cereulides, at 2.5 ng ml⁻¹ (trace 2) or 6.5 ng ml⁻¹ (trace 3), in medium with KCl. Trace 1, vehicle only (methanol). The panels show traces typical of three identical experiments using different mitochondrial preparations. FCCP, carbonyl cyanide-p-trifluoromethoxyphenylhydrazone.