Effect of burn and first-pass splanchnic leucine extraction on protein kinetics in rats

Journal Article · Mon Aug 01 04:00:00 EDT 1988 · Am. J. Physiol.; (United States)

OSTI ID:6769234

Karlstad, M D; DeMichele, S J; Istfan, N; Blackburn, G L; Bistrian, B R

The effects of burn and first-pass splanchnic leucine extraction (FPE) on protein kinetics and energy expenditure were assessed by measuring O/sub 2/ consumption, CO/sub 2/ production, nitrogen balance, leucine kinetics, and tissue fractional protein synthetic rates (FSR-%/day) in enterally fed rats. Anesthetized male rats (200 g) were scalded on their dorsum with boiling water (25-30% body surface area) and enterally fed isovolemic diets that provided 60 kcal/day and 2.4 g of amino acids/day for 3 days. Controls were not burned. An intravenous or intragastric infusion of L-(1-/sup 14/C)leucine was used to assess protein kinetics on day 3. FPE was taken as the ratio of intragastric to intravenous plasma leucine specific activity. There was a 69% reduction in cumulative nitrogen balance (P less than 0.001) and a 17-19% increase in leucine oxidation (P less than 0.05) and total energy expenditure (P less than 0.01) in burned rats. A 15% decrease in plasma leucine clearance (P less than 0.05) was accompanied by a 20% increase in plasma (leucine) (P less than 0.01) in burned rats. Burn decreased rectus muscle FSR from 5.0 +/- 0.4 to 3.5 +/- 0.5 (P less than 0.05) and increased liver FSR from 19.0 +/- 0.5 to 39.2 +/- 3.4 (P less than 0.01). First pass extraction of dietary leucine by the splanchnic bed was 8% in controls and 26% in burned rats. Leucine kinetics corrected for FPE showed increased protein degradation with burn that was not evident without FPE correction. This hypermetabolic burn model can be useful in the design of enteral diets that optimize rates of protein synthesis and degradation.

• Research Organization: Univ. of Tennessee College of Medicine, Knoxville (USA)
• OSTI ID: 6769234
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 255; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
BLOOD-PLASMA CLEARANCE
BURNS
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CLEARANCE
DIET
ELEMENTS
INJURIES
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LEUCINE
MAMMALS
METABOLISM
NITROGEN
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PROTEINS
RATS
REACTION KINETICS
RESPIRATION
RODENTS
TRACER TECHNIQUES
VERTEBRATES