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Protein Dynamics during Refeeding of Protein-Depleted Rats: Effects of Increasing Amino Acid Intake by TPN or Enteral Continuous Feeding
- Source :
- The Journal of Nutrition. 114:75-88
- Publication Year :
- 1984
- Publisher :
- Elsevier BV, 1984.
-
Abstract
- The effect of increasing nitrogen intake with constant calorie supply was studied in protein-depleted rats. Animals were randomized into three paired groups to receive either total parenteral nutrition (TPN) or enteral (EF) isocaloric feedings (240 kcal X kg-1 X day-1) differing only in their amount of amino acids. The diets, composed of dextrose, a safflower oil emulsion and crystalline amino acids, were infused continuously for 5 days. Daily nitrogen intakes were for controls (EF, n = 7; TPN, n = 6) 0.25 g/kg; for groups 1 (EF, n = 7; TPN, n = 8) 1.4 g/kg and for groups 2 (EF, n = 7; TPN, n = 7) 2.5 g/kg. The rats in groups 1 and 2 obtained significant protein repletion in terms of body weight, nitrogen retention, liver protein and serum albumin regardless of the route of nutrient delivery. However, rats in groups 2 (higher nitrogen intake) presented a more rapid and greater recovery despite a reduction in nitrogen utilization. Whole-body leucine kinetics studied at the end of controlled feeding periods were similar for EF and TPN rats. However, increasing nitrogen intake (1 and 2) increased whole-body leucine flux and incorporation into protein resulting in a better balance, since leucine release from protein breakdown was comparable to controls. Liver protein fractional synthetic rates were reduced in EF while remaining at a high rate in TPN group 2 and still more elevated in TPN group 1, suggesting a preferential support of liver protein by enteral feeding or the effect of TPN as a non-physiologic route.
- Subjects :
- Parenteral Nutrition
medicine.medical_specialty
Calorie
Nitrogen
Serum albumin
Medicine (miscellaneous)
Biology
Enteral administration
Enteral Nutrition
Nutrient
Leucine
Protein Deficiency
Internal medicine
medicine
Animals
Amino Acids
chemistry.chemical_classification
Nutrition and Dietetics
Muscles
Body Weight
Proteins
Rats, Inbred Strains
Rats
Amino acid
Protein catabolism
Parenteral nutrition
Endocrinology
Liver
chemistry
biology.protein
Female
Parenteral Nutrition, Total
Energy Intake
Subjects
Details
- ISSN :
- 00223166
- Volume :
- 114
- Database :
- OpenAIRE
- Journal :
- The Journal of Nutrition
- Accession number :
- edsair.doi.dedup.....3e798d169e1be95726b4fe48f136a0b7