Whole body protein kinetics measured with a non-invasive method in severely burned children.
Persistent and extensive skeletal muscle catabolism is characteristic of severe burns. Whole body protein metabolism, an important component of this process, has not been measured in burned children during the long-term convalescent period. The aim of this study was to measure whole body protein turnover in burned children at discharge (95% healed) and in healthy controls by a non-invasive stable isotope method. Nine burned children (7 boys, 2 girls; 54±14 (S.D.)% total body area burned; 13±4 years; 45±20 kg; 154±14 cm) and 12 healthy children (8 boys, 4 girls; 12±3 years; 54±16 kg; 150±22 cm) were studied. A single oral dose of (15)N-alanine (16 mg/kg) was given, and thereafter urine was collected for 34 h. Whole body protein flux was calculated from labeling of urinary urea nitrogen. Then, protein synthesis was calculated as protein flux minus excretion, and protein breakdown as flux minus intake. At discharge, total protein turnover was 4.53±0.65 (S.E.)g kg body weight(-1) day(-1) in the burned children compared to 3.20±0.22 g kg(-1) day(-1) in controls (P=0.02). Expressed relative to lean body mass (LBM), the rates were 6.12±0.94 vs. 4.60±0.36 g kg LBM(-1) day(-1) in burn vs. healthy (P=0.06). Total protein synthesis was also elevated in burned vs. healthy children, and a tendency for elevated protein breakdown was observed.


CONCLUSIONS
Total protein turnover is elevated in burned children at discharge compared to age-matched controls, possibly reflecting the continued stress response to severe burn. The oral (15)N-alanine bolus method is a convenient, non-invasive, and no-risk method for measurement of total body protein turnover.
Børsheim
Elisabet
E
Shriners Hospitals for Children/Galveston, Department of Surgery, University of Texas Medical Branch, Galveston, TX 77550, USA. elborshe@utmb.edu
Chinkes
David L
DL
McEntire
Serina J
SJ
Rodriguez
Nancy R
NR
Herndon
David N
DN
Suman
Oscar E
OE
D000293:Adolescent; D000409:Alanine / Q000008:administration & dosage; D002056:Burns / Q000378:metabolism*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009124:Muscle Proteins / Q000378:metabolism; D009584:Nitrogen / Q000652:urine; D009587:Nitrogen Isotopes / Q000008:administration & dosage / Q000652:urine; D014176:Protein Biosynthesis; D011506:Proteins / Q000378:metabolism*; D014508:Urea / Q000652:urine
D009124:Muscle Proteins; D009587:Nitrogen Isotopes; D011506:Proteins; D014508:Urea; D009584:Nitrogen; D000409:Alanine
Proc Nutr Soc. 1978 May;37(1):22A
662847
Am J Physiol. 1996 Apr;270(4 Pt 1):E627-33
8928769
Fed Proc. 1978 Jul;37(9):2283-90
350634
J Biol Chem. 1949 Sep;180(2):715-26
18147157
J Am Coll Surg. 2006 Mar;202(3):536-48
16500259
J Nutr. 2001 Oct;131(10):2659-63
11584087
Med Sci Sports Exerc. 1999 Mar;31(3):378-85
10188741
J Burn Care Res. 2009 Jan-Feb;30(1):77-82
19060732
Med Sci Sports Exerc. 2002 May;34(5):820-7
11984301
Pediatr Res. 1996 Mar;39(3):401-9
8929858
Expert Opin Pharmacother. 2008 Aug;9(11):1895-908
18627328
Nutrition. 2009 Mar;25(3):261-9
19097858
Clin Nutr. 2004 Apr;23(2):153-60
15030954
Diabetes Metab Rev. 1989 May;5(3):213-26
2656153
Burns. 2008 Jun;34(4):452-9
18243565
Ann Surg. 2008 Sep;248(3):387-401
18791359
J Clin Endocrinol Metab. 2002 Jul;87(7):3378-84
12107253
Metabolism. 1978 Jan;27(1):27-34
339034
Clin Sci (Lond). 1985 Mar;68(3):271-82
3918824
J Burn Care Rehabil. 1994 Mar-Apr;15(2):174
8195260
Am J Physiol. 1978 Aug;235(2):E165-74
686164
Metabolism. 1973 Feb;22(2):179-207
4567003
Br J Nutr. 2005 Aug;94(2):141-53
16115347
Am J Clin Nutr. 2006 Sep;84(3):475-82
16960159
Metabolism. 1998 Dec;47(12):1434-9
9867070