title: Neonatal Respiratory Diseases in the Newborn Infant: Novel Insights from Stable Isotope Tracer Studies.
abstract: Respiratory distress syndrome is a common problem in preterm infants and the etiology is multifactorial. Lung underdevelopment, lung hypoplasia, abnormal lung water metabolism, inflammation, and pulmonary surfactant deficiency or disfunction play a variable role in the pathogenesis of respiratory distress syndrome. High-quality exogenous surfactant replacement studies and studies on surfactant metabolism are available; however, the contribution of surfactant deficiency, alteration or dysfunction in selected neonatal lung conditions is not fully understood. In this article, we describe a series of studies made by applying stable isotope tracers to the study of surfactant metabolism and lung water. In a first set of studies, which we call 'endogenous studies', using stable isotope-labelled intravenous surfactant precursors, we showed the feasibility of measuring surfactant synthesis and kinetics in infants using several metabolic precursors including plasma glucose, plasma fatty acids and body water. In a second set of studies, named 'exogenous studies', using stable isotope-labelled phosphatidylcholine tracer given endotracheally, we could estimate surfactant disaturated phosphatidylcholine pool size and half-life. Very recent studies are focusing on lung water and on the endogenous biosynthesis of the surfactant-specific proteins. Information obtained from these studies in infants will help to better tailor exogenous surfactant treatment in neonatal lung diseases.
authors.affiliation: Division of Neonatology, Salesi Hospital and Polytechnic University of Marche, Ancona, Italy.
authors.forename: Virgilio P
authors.initials: VP
authors.lastname: Carnielli
authors.forename: Chiara
authors.initials: C
authors.lastname: Giorgetti
authors.forename: Manuela
authors.initials: M
authors.lastname: Simonato
authors.forename: Luca
authors.initials: L
authors.lastname: Vedovelli
authors.forename: Paola
authors.initials: P
authors.lastname: Cogo
mesh_terms: D065630:Hernias, Diaphragmatic, Congenital / Q000188:drug therapy; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007554:Isotopes / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008168:Lung / Q000503:physiopathology*; D008471:Meconium Aspiration Syndrome / Q000188:drug therapy; D010713:Phosphatidylcholines / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011014:Pneumonia / Q000188:drug therapy; D011663:Pulmonary Surfactants / Q000008:administration & dosage / Q000493:pharmacokinetics*; D012127:Respiratory Distress Syndrome, Newborn / Q000188:drug therapy
chemical_list: D007554:Isotopes; D010713:Phosphatidylcholines; D011663:Pulmonary Surfactants; C017463:lecithins, disaturated