Assessment of Endogenous Nitric Oxide Formation in Newborns: Measurement of Urinary Nitrite and Nitrate Concentrations

Hirokazu Tsukahara, Motohiro Takeuchi, Ikue Hata, Masahiro Hiraoka, Fumikazu Kotsuji, Masakatsu Sudo, Mitsufumi Mayumi

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11 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)322-326
Number of pages5
Issue number5
Publication statusPublished - Jan 1 1997
Externally publishedYes



  • Newborns
  • Nitric oxide
  • Respiratory distress syndrome
  • Urinary nitrate
  • Urinary nitrite

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Developmental Biology

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