We measured the urinary nitrite and nitrate (NOx–) excretion, an index of endogenous nitric oxide formation, in term and preterm newborns on the 1st and 4th days of age. In the infants of both groups, the urinary NOx– excretion significantly increased from the 1st to the 4th day. The urinary NOx– excretion in preterm infants was significantly higher as compared with term babies on both days. Furthermore, the urinary NOx– excretion was significantly elevated in preterm infants with respiratory distress syndrome as compared with those without cardiopulmonary complications on the 4th day. These changes of urinary NOx–; excretion in newborns strongly suggest the presence of an active physiological role for nitric oxide in the circulatory adaptation to extrauterine life.
- Nitric oxide
- Respiratory distress syndrome
- Urinary nitrate
- Urinary nitrite
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health
- Developmental Biology