Metabolic precursors of surfactant disaturated-phosphatidylcholine in preterms with respiratory distress

J Lipid Res. 2009 Nov;50(11):2324-31. doi: 10.1194/jlr.M800514-JLR200. Epub 2009 May 27.

Abstract

Our objective was to study the metabolic precursors of surfactant disaturated-phosphatidylcholine (DSPC) in preterm infants with respiratory distress syndrome (RDS) on mechanical ventilation. We performed 46 DSPC kinetic studies in 23 preterms on fat-free parenteral nutrition and mechanical ventilation (birth weight = 1167 +/- 451 g, gestational age = 28.5 +/- 2.0 weeks). Eight infants received a simultaneous intravenous infusion of U(13)C-glucose and [16,16,16](2)H-palmitate, eight infants received U(13)C-glucose and (2)H(2)O, and seven received U(13)C-palmitate and (2)H(2)O. Surfactant DSPC kinetics were calculated from the isotopic enrichments of DSPC-palmitate from sequential tracheal aspirates and its metabolic precursors in plasma or urine. DSPC fractional synthesis rate (FSR) was 17 +/- 11, 21 +/- 16, and 15 +/- 6%/day from glucose, palmitate, and body water, respectively (P = 0.36). DSPC-FSR from U(13)C-glucose and (2)H(2)O were significantly correlated and yielded similar estimates (difference of -0.1 +/- 3%) (P = 0.91). The difference in the 15 infants receiving palmitate versus (2)H(2)O or palmitate versus glucose was +6.0 +/- 12%/day (P = 0.21). There was a significant correlation between DSPC-FSRs from plasma glucose and plasma FFA. The contribution of glucose versus palmitate to DSPC-FSR was 49 +/- 20% versus 51 +/- 20%, respectively. Plasma glucose and FFA showed similar contributions to DSPC-FSR in infants with RDS and fat-free parenteral nutrition. FSRs from (2)H(2)O or glucose were highly correlated.

Publication types

  • Clinical Trial

MeSH terms

  • Analysis of Variance
  • Blood Glucose / metabolism
  • Carbon Isotopes
  • Chromatography, Gas
  • Deuterium
  • Gestational Age
  • Glucose / administration & dosage
  • Humans
  • Infant, Newborn
  • Infant, Premature
  • Infusions, Intravenous
  • Kinetics
  • Mass Spectrometry
  • Palmitates / administration & dosage
  • Palmitates / blood
  • Palmitates / urine
  • Phosphatidylcholines / metabolism*
  • Pulmonary Surfactants / metabolism*
  • Respiration, Artificial
  • Respiratory Distress Syndrome, Newborn / metabolism*
  • Respiratory Distress Syndrome, Newborn / therapy
  • Time Factors
  • Water / administration & dosage
  • Water / metabolism

Substances

  • Blood Glucose
  • Carbon Isotopes
  • Palmitates
  • Phosphatidylcholines
  • Pulmonary Surfactants
  • lecithins, disaturated
  • Water
  • Deuterium
  • Glucose