Figure 1.

Oxidative stress pathways capable of producing reactive oxidant species. These pathways include nitric oxide synthase pathway, xanthine oxidase pathway, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase pathway, and mitochondrial oxidant-generating pathway. The mitochondrial oxidant-generating pathway is key to oxidative damage of diaphragm muscle inactivity. O₂⁺ superoxide; NO⁺, nitric oxide. Adapted with permission from [21].