title: Stimulated nitric oxide production and arginine deficiency in children with cystic fibrosis with nutritional failure.
abstract: OBJECTIVE
  To determine whether upregulated whole body de novo arginine synthesis and protein breakdown are present as a compensatory mechanism to meet the increased demand for arginine and nitric oxide (NO) production in pediatric patients with cystic fibrosis (CF) and nutritional failure.
  
  
  METHODS
  In 16 children with CF, studied at the end of antibiotic treatment for a pulmonary exacerbation, and 17 healthy controls, whole body arginine, citrulline (Cit), and protein turnover were assessed by stable isotope methodology and de novo arginine synthesis, arginine clearance, NO synthesis, protein synthesis and breakdown, and net protein balance were calculated. The plasma isotopic enrichments and amino acid concentrations were measured by liquid chromatography-tandem mass spectrometry.
  
  
  RESULTS
  Increased arginine clearance was found in patients with CF (P < .001), whereas whole body NO production rate and plasma arginine levels were not different. Whole body arginine production (P < .001), de novo arginine synthesis, and protein breakdown and synthesis (P < .05) were increased in patients with CF, but net protein balance was comparable. Patients with CF with nutritional failure (n = 7) had significantly higher NO production (P < .05), de novo arginine synthesis, Cit production (P < .001), and plasma Cit concentration (P < .05) and lower plasma arginine concentration (P < .05) than those without nutritional failure (n = 9).
  
  
  CONCLUSIONS
  Nutritional failure in CF is associated with increased NO production. However, up-regulation of de novo arginine synthesis and Cit production was not sufficient to meet the increased arginine needs leading to arginine deficiency.
authors: Department of Geriatrics, Center for Translational Research in Aging and Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA. mpkj.engelen@ctral.org
authors: Mariëlle P K J
authors: MP
authors: Engelen
authors: Gulnur
authors: G
authors: Com
authors: Yvette C
authors: YC
authors: Luiking
authors: Nicolaas E P
authors: NE
authors: Deutz
mesh_terms: D000293:Adolescent; D001120:Arginine / Q000172:deficiency*; D002648:Child; D015362:Child Nutrition Disorders / Q000150:complications* / Q000378:metabolism*; D003550:Cystic Fibrosis / Q000150:complications* / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000096:biosynthesis*; D055815:Young Adult
chemical_list: D009569:Nitric Oxide; D001120:Arginine
keywords: ADMA; Arg; Arginine; Asymmetric dimethyl arginine; CF; Cit; Citrulline; Cystic fibrosis; FEV(1); FFM; FM; Fat mass; Fat-free mass; FeNO; Forced expiratory volume in 1 second; Fractional exhaled nitric oxide; NO; Nitric oxide; Orn; Ornithine; WbRa; Whole body rate of appearance