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Nutritional efficiency of alpha-ketoisocaproate relative to leucine, assessed isotopically
- Source :
- American Journal of Physiology-Endocrinology and Metabolism. 249:E355-E359
- Publication Year :
- 1985
- Publisher :
- American Physiological Society, 1985.
-
Abstract
- The efficiency of alpha-ketoisocaproate as a dietary substitute for leucine was assessed in rats by two techniques: first, the minimal dose of alpha-ketoisocaproate required, as a supplement to a leucine-free diet, to achieve a growth rate as great as animals receiving leucine was found to be between 2.2 and 4.4 times larger. Therefore the nutritional efficiency of alpha-ketoisocaproate lies between 0.23 and 0.46. Second, alpha-[1-14C]-ketoisocaproate and [3H]leucine were administered orally and the ratio of 14C/3H incorporated into the leucine of whole-body protein and fibrin was measured. This ratio, divided by the ratio 14C/3H injected, was the same in fibrin as in whole-body protein and averaged 0.39. Thus both techniques yield the same value, within the error of measurement, for the relative nutritional efficiency of alpha-ketoisocaproate. We also found that alpha-ketoisocaproate feeding at varying dosage did not alter this ratio in whole-body protein (measured in rats fasted overnight), suggesting that neither wide variations in growth rate nor exposure for 10 days to alpha-ketoisocaproate (in a diet of constant protein content) alters the relative rates of utilization (or oxidation) of alpha-ketoisocaproate vs. leucine.
- Subjects :
- Male
Alpha-ketoisocaproate
medicine.medical_specialty
Physiology
Transamination
Endocrinology, Diabetes and Metabolism
Tritium
Fibrin
Protein content
Eating
Animal science
Leucine
Physiology (medical)
Internal medicine
medicine
Animals
Nutritional Physiological Phenomena
Carbon Radioisotopes
Growth rate
chemistry.chemical_classification
Dose-Response Relationship, Drug
biology
Body Weight
Rats, Inbred Strains
Keto Acids
Diet
Rats
Amino acid
Dose–response relationship
Endocrinology
Biochemistry
chemistry
Protein Biosynthesis
biology.protein
Subjects
Details
- ISSN :
- 15221555 and 01931849
- Volume :
- 249
- Database :
- OpenAIRE
- Journal :
- American Journal of Physiology-Endocrinology and Metabolism
- Accession number :
- edsair.doi.dedup.....8025c8765c7967bea003a59842d4242e
- Full Text :
- https://doi.org/10.1152/ajpendo.1985.249.4.e355