Arginine flux and intravascular nitric oxide synthesis in severe childhood undernutrition.
BACKGROUND
Although nutritionally dispensable amino acids are not essential in the diet, adequate synthesis is necessary for maintenance of good health. Whereas children with edematous severe childhood undernutrition (SCU) can maintain production rates of glycine and serine despite a slower body protein breakdown rate, it is unknown whether the same is true for the semidispensable amino acid arginine.


OBJECTIVE
We aimed to measure arginine flux and intravascular nitric oxide synthesis in children with SCU.


METHODS
Arginine flux and the fractional and absolute synthesis rates of plasma nitrite plus nitrate were measured postabsorptively by using a 6-h infusion of [(15)N(2)]-arginine in 2 groups of children with edematous (n = 14) or nonedematous (n = 7) SCU when they were infected and malnourished (postadmission day approximately 3; clinical phase 1), when they were no longer infected (postadmission day approximately 15; clinical phase 2), and when they were recovered (postadmission day approximately 55; clinical phase 3).


RESULTS
Arginine flux was slower (P < 0.01) and plasma arginine concentrations were lower in the edematous group than in the nonedematous group at clinical phase 1. At clinical phase 2, flux doubled to a value that was not significantly different from the value at clinical phase 3. There were no significant differences in the plasma concentration or fractional or absolute synthesis rate of plasma nitrite plus nitrate between the groups at any clinical phase and among clinical phases within each group.


CONCLUSIONS
Whereas children with nonedematous SCU can maintain arginine flux at the same rate as when recovered, children with edematous SCU cannot. The slower arginine flux was not, however, associated with slower nitric oxide synthesis.
Jahoor
Farook
F
US Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030-2600, USA. fjahoor@bcm.tmc.edu
Badaloo
Asha
A
Villalpando
Salvador
S
Reid
Marvin
M
Forrester
Terrence
T
D001120:Arginine / Q000097:blood / Q000378:metabolism*; D016022:Case-Control Studies; D004487:Edema / Q000150:complications / Q000378:metabolism* / Q000628:therapy; D005260:Female; D006801:Humans; D007223:Infant; D007228:Infant Nutrition Disorders / Q000150:complications / Q000378:metabolism* / Q000628:therapy; D007239:Infections / Q000150:complications / Q000378:metabolism* / Q000628:therapy; D007732:Kwashiorkor / Q000150:complications / Q000378:metabolism* / Q000628:therapy; D008297:Male; D009566:Nitrates / Q000097:blood / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis*; D009573:Nitrites / Q000097:blood / Q000378:metabolism; D009587:Nitrogen Isotopes; D011502:Protein-Energy Malnutrition / Q000150:complications / Q000378:metabolism* / Q000628:therapy
D009566:Nitrates; D009573:Nitrites; D009587:Nitrogen Isotopes; D009569:Nitric Oxide; D001120:Arginine