Effect of a prolonged protein-free diet on cell size, protein synthesis and degradation of rat liver.
Rats were fed a protein-free diet. After 9 weeks the animals' weight decreased to about 50% of the original. The liver weight was also decreased to about half, and most interestingly the average size of the liver cells was reduced about 50%. Liver protein synthesis was approximately 75% of controls tested in an "in vitro" system. Polysomes were found disaggregated in livers of rats on protein-free diet. This was not due to a reduced content or translatability of mRNA. eIF-2 partially purified from livers of rats on protein-free diet had the same activity as that from controls. The decrease of ATP, ADP and AMP in livers of rats on protein-free diet (19%, 42% and 58% respectively) may be responsible for the decreased rate of initiation of protein synthesis. Proteolysis in liver cytosol from rats on protein-free diet was 50% higher than in controls mostly due to lysosomal proteolysis.
Felipo
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Instituto de Investigaciones Citológicas, Centro Asociado del C.S.I.C., Valencia, Spain.
Miñana
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D000227:Adenine Nucleotides / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D008099:Liver / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008970:Molecular Weight; D009929:Organ Size; D011132:Polyribosomes / Q000648:ultrastructure; D014176:Protein Biosynthesis; D011502:Protein-Energy Malnutrition / Q000378:metabolism* / Q000473:pathology; D011506:Proteins / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values
D000227:Adenine Nucleotides; D011506:Proteins