Membrane potential and H2O2 production in duodenal mitochondria from broiler chickens (Gallus gallus domesticus) with low and high feed efficiency

Increased hydrogen peroxide (H2O2) production was observed in duodenal mitochondria obtained from broiler chickens with low feed efficiency (FE). As a decrease in mitochondrial membrane potential (▵ψm) due to mild uncoupling of oxidative phosphorylation reduces reactive oxygen species production, this study was conducted to evaluate the effect of uncoupling on ▵ψm and H2O2 production in duodenal mitochondria isolated from broilers with low (0.48 ± 0.02) and high (0.68 ± 0.01) FE. Membrane potential and H2O2 production were measured fluorometrically and in the presence of different levels of an uncoupler, carbonylcyanide-p-trifluoromethoxyphenylhydrazone (FCCP). The ▵ψm was higher (P ≤ 0.05) in high FE mitochondria at 0 to 600 nM FCCP. A decrease in ▵ψm was observed at 600 and 1000 nM FCCP in the low and high FE groups, respectively. H2O2 generation was higher in the low FE mitochondria at all FCCP levels except at 200 nM. Adding 200 to 800 nM FCCP decreased H2O2 production in low but not in high FE mitochondria. These results showed that FCCP-induced uncoupling lowered H2O2 production in low FE but not in high FE duodenal mitochondria and suggest that ▵ψm may influence H2O2 production in low FE mitochondria.