Figure 5.

Steady-state behavior of respiration, NADH, and ΔΨ_m as a function of mitochondrial membrane uncoupling. Freshly isolated guinea pig heart mitochondria were subjected up to 100 nM FCCP, an uncoupler of mitochondrial respiration. Respiration (A) and NADH, ΔΨ_m (C) were evaluated as described in the Materials and Methods. To simulate the experimental protocol shown in panel A, the proton conductance (g_h) in the ME-R model was increased from 2 × 10⁻⁶ to 3.5 × 10⁻⁵ mM ms⁻¹ mV⁻¹. Under these conditions, the steady-state values of respiration (V_O2) from both complex I and II (B), and NADH and ΔΨ_m (D) are represented.