Figure 1.

Nitric oxide dependent hydroxyl radical generation in neonatal hypoxia ischemia brain injury.

Neonatal brain possess a number of enzymatic systems such as NADPH oxidases, xanthine oxidase, and mitochondria that generate reactive oxygen species, under hypoxia ischemia condition, can cause brain injury. When high concentration of superoxide is present, hydrogen peroxide (H₂O₂) produces highly reactive hydroxyl radical (^–OH), with Fe²⁺ through Fenton reaction. Nitric oxide modifies the [4Fe–4S] clusters of aconitase to iron response protein 1 (IRP-1) and regulates cellular iron homeostasis, which responds to the hypoxia ischemia induced hydroxyl radical generation.