Urinary excretion of the nitrotyrosine metabolite 3-nitro-4-hydroxyphenylacetic acid in preterm and term infants

Background: Newborn infants are exposed to various sources of oxidative and/or nitrative stress which refers to either oxidation and/or nitration of endogenous proteins including loss of their original function. Nitrative stress is predominantly caused following synthesis of peroxynitrite. Particularly preterm infants with immature defense mechanisms against free radical injury appear at risk. Objective: To test the feasibility of quantifying the degradation products of the peroxynitrite marker nitrotyrosine [3-nitro-4-hydroxyphenylacetic acid (NHPA) and para-hydroxyphenylacetic acid (PHPA)] in neonatal urine sa…