title: S-Nitrosylated fetal hemoglobin in neonatal human blood.
abstract: Nitric oxide (NO) and its derivatives play important roles in the cardiopulmonary transition upon birth and in other oxygen-sensitive developmental milestones. One mechanism for the coupling of oxygen sensing and signaling by NO species is via the formation of an S-nitrosothiol (SNO) moiety on hemoglobin (Hb, forming SNO-Hb) and its release from the red blood cell in hypoxia. Although SNO-Hb formed on adult-type Hb (HbA, forming SNO-HbA) has been documented in physiological and pathophysiological human states, the fetal variant, SNO-HbF, has thus far not been isolated or characterized in human blood.
  
  
  
  We developed a technique capable of separating Hbs A and F under conditions that preserve SNO. We then measured SNO-HbF in the blood of healthy and premature or otherwise ill neonates using the gold standard for SNO measurement, mercury-coupled photolysis-chemiluminescence. SNO-HbF levels were in the range of those previously reported for HbA in adults. We found that SNO-HbF was more abundant at earlier gestational age (<30 weeks), even when accounting for the absolute HbF level.
  
  
  
  The ability to monitor SNO-HbF could provide new insights into fetal development and the perinatal transition, and has potential as a biomarker relevant to the management of neonatal diseases.
authors.affiliation: Department of Medicine, Duke University and Durham VA Medical Centers, Durham, NC 27710, USA.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Riccio
authors.affiliation: Department of Pediatrics, Duke University, Durham, NC 27710, USA.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Malowitz
authors.affiliation: Department of Pediatrics, Duke University, Durham, NC 27710, USA.
authors.forename: C Michael
authors.initials: CM
authors.lastname: Cotten
authors.affiliation: Department of Obstetrics and Gynecology, Duke University, Durham, NC 27710, USA.
authors.forename: Amy P
authors.initials: AP
authors.lastname: Murtha
authors.affiliation: Department of Medicine, Duke University and Durham VA Medical Centers, Durham, NC 27710, USA. Electronic address: tim.mcmahon@duke.edu.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: McMahon
mesh_terms: D000375:Aging / Q000097:blood*; D002852:Chromatography, Ion Exchange / Q000379:methods*; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D005865:Gestational Age; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D006454:Hemoglobins; C103574:S-nitrosohemoglobin
keywords: Erythrocyte; Hydroxyurea; Nitric oxide; Perinatology; Prematurity; S-nitrosothiols