Hypoxia-ischemia in fetal rabbit brain increases reactive nitrogen species production: quantitative estimation of nitrotyrosine.

Reactive nitrogen species (RNS) cause nitration of protein-bound tyrosine that is used as biomarker for detection. We hypothesized that RNS are formed in fetal rabbit brain following acute placental insufficiency. Near-term pregnant rabbits were randomized to either repetitive uterine ischemia or no ischemia, and fetal brains obtained. Only one electrochemical HPLC method (of three tested) was successful in detecting brain nitrotyrosine. Protein nitrotyrosine was significantly increased following cumulative 40 min ischemia and 20 min reperfusion compared to controls. Repetitive hypoxia-ischemia results in the increased formation of RNS in near-term fetal brains.