title: Stable precursor fragments of vasoactive peptides in umbilical cord blood of term and preterm infants.
abstract: BACKGROUND
  Though various neurohormonal systems are concurrently activated during birth, their biological effectors are not always easy to measure due to their short half-life in vivo, instability in biological samples, or very low concentrations.
  
  
  METHODS
  Using a recently discovered chemiluminescence assay, we measured the stable precursor fragments mid-regional pro-atrial natriuretic peptide (MR-proANP), mid-regional pro-adrenomedullin (MR-proADM), C-terminal pro-endothelin-1 (CT-proET-1) and C-terminal pro-vasopressin (CT-proAVP or copeptin) immediately after birth in umbilical venous cord blood from 119 infants with a gestational age of 23-42 weeks and evaluated their possible functions.
  
  
  RESULTS
  Cord blood levels of MR-proANP, MR- proADM, CT-proET-1, and CT-proAVP were considerably higher compared with normal adult levels. The CT-proAVP concentrations were 10-fold higher in term, and 70-fold higher in extremely preterm infants. MR-proANP showed 4-fold higher levels in term infants and 20-fold higher levels in extremely preterm infants. Levels of MR-proADM and CT-proET-1 were 2- to 3-fold higher in preterm and term infants. All four parameters showed significantly decreased values with increasing gestational age and a significant correlation between CT-proET-1 and MR-proADM.
  
  
  CONCLUSIONS
  Our results indicate that vasoactive and natriuretic mediators play a functionally relevant role in circulatory transition from fetal to neonatal life.
authors: Division of Neonatology, Department of Pediatrics, University of Heidelberg Medical School, Im Neuenheimer Feld 430, Heidelberg, Germany. lutz.koch @ med.uni-heidelberg.de
authors: L
authors: L
authors: Koch
authors: M T
authors: MT
authors: Dabek
authors: D
authors: D
authors: Frommhold
authors: J
authors: J
authors: Poeschl
mesh_terms: D053607:Adrenomedullin / Q000097:blood*; D000328:Adult; D009320:Atrial Natriuretic Factor / Q000097:blood*; D019332:Endothelin-1 / Q000097:blood*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D005865:Gestational Age; D006020:Glycopeptides / Q000097:blood*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood*; D008297:Male; D010446:Peptide Fragments / Q000097:blood*; D011498:Protein Precursors / Q000097:blood*; D012189:Retrospective Studies; D014667:Vasopressins / Q000097:blood
chemical_list: C557077:C-terminal proendothelin-1; D019332:Endothelin-1; D006020:Glycopeptides; D010446:Peptide Fragments; D011498:Protein Precursors; C048197:copeptins; C552580:midregional pro-atrial natriuretic peptide, human; C453701:proAVP hormone; D014667:Vasopressins; D053607:Adrenomedullin; D009320:Atrial Natriuretic Factor