Mitochondrial ATP‐sensitive K+ channel opening decreases reactive oxygen species generation

Abstract

Mitochondrial ATP‐sensitive K⁺ channel (mitoK_ATP) opening was shown previously to slightly increase respiration and decrease the membrane potential by stimulating K⁺ cycling across the inner membrane. Here we show that mitoK_ATP opening reduces reactive oxygen species generation in heart, liver and brain mitochondria. Decreased H₂O₂ release is observed when mitoK_ATP is active both with respiration stimulated by oxidative phosphorylation and when ATP synthesis is inhibited. In addition, decreased H₂O₂ release is observed when mitochondrial ΔpH is enhanced, an effect expected to occur when mitoK_ATP is open. We conclude that mitoK_ATP is an effective pathway to trigger mild uncoupling, preventing reactive oxygen species release.