Back to Search
Start Over
Relationship Between Protein Intake and Hepatic Protein Synthesis in Rats
- Source :
- The Journal of Nutrition. 121:1581-1590
- Publication Year :
- 1991
- Publisher :
- Elsevier BV, 1991.
-
Abstract
- Protein synthesis has been measured in vitro in postmitochondrial extracts from livers of rats fed levels of casein ranging from 0 to 40% by weight. The maximal capacity for protein synthesis per milligram of RNA, measured with each amino acid added at 250 mumol/L, was 40-60% higher in rats fed a protein-free diet than in those fed 6 or 15% casein. Our results suggest that the livers of rats fed a protein-free diet are primed for the synthesis of tissue proteins and, given an adequate supply of amino acids, the rate of protein synthesis would be as high as or higher than the rate in protein-replete animals. When amino acids were added to the in vitro system at concentrations found in plasma of rats fed 0, 6, 15 or 40% casein the rate of protein synthesis increased by three- to fourfold over this range, with the highest rate observed for the 15% dietary casein level. We conclude that when protein intake is below the requirement level, the rate of liver protein synthesis may be limited by amino acid supply, by the capacity of the system for protein synthesis or by both.
- Subjects :
- Male
medicine.medical_specialty
Medicine (miscellaneous)
Biology
chemistry.chemical_compound
Biosynthesis
Internal medicine
Casein
medicine
Protein biosynthesis
Animals
Amino Acids
chemistry.chemical_classification
Nutrition and Dietetics
Caseins
RNA
Rats, Inbred Strains
Metabolism
Protein intake
In vitro
Rats
Amino acid
Endocrinology
Liver
chemistry
Protein Biosynthesis
Dietary Proteins
Subjects
Details
- ISSN :
- 00223166
- Volume :
- 121
- Database :
- OpenAIRE
- Journal :
- The Journal of Nutrition
- Accession number :
- edsair.doi.dedup.....0bbac08b4ac418be3dffeb971b255457