scholarly journals Incorporation of radioactive amino acids into serum albumin by isolated rat-liver ribosomes

1962 ◽  
Vol 83 (1) ◽  
pp. 69-74 ◽  
Author(s):  
A KORNER
Keyword(s):  
Amino Acids ◽  
Serum Albumin ◽  
Rat Liver ◽  
Isolated Rat Liver ◽  
Isolated Rat ◽  
Liver Ribosomes

scholarly journals The effects L-leucine on the synthesis of urea, glutamate and glutamine by isolated rat liver cells

1975 ◽  
Vol 146 (2) ◽  
pp. 457-464 ◽  
Author(s):  
J M Mourão ◽  
J D McGivan ◽  
J B Chappell
Keyword(s):  
Amino Acids ◽  
Nitrogen Source ◽  
Glutamate Dehydrogenase ◽  
Rat Liver ◽  
Liver Cells ◽  
Carbamoyl Phosphate ◽  
Isolated Cells ◽  
Isolated Rat Liver ◽  
Rat Liver Cells ◽  
Isolated Rat

With either alanine or a mixture of 15 different amino acids as nitrogen source, the addition of L-leucine inhibited the synthesis of urea by isolated rat liver cells. With alanine present leucine promoted the production of glutamate and glutamine. Comparison of effects of leucine on soluble glutamate dehydrogenase, mitochondria and isolated cells supports the postulate that leucine exerts its effect through activation of glutamate dehydrogenase. It is suggested that this latter enzyme may not be as important for the production of NH3 for carbamoyl phosphate synthesis as has been considered hitherto.

scholarly journals Inhibition of protein synthesis by ricin: experiments with rat liver mitochondria and nuclei and with ribosomes from Escherichia coli

1974 ◽  
Vol 142 (3) ◽  
pp. 695-697 ◽  
Author(s):  
Margherita Greco ◽  
Lucio Montanaro ◽  
Francesco Novello ◽  
Cecilia Saccone ◽  
Simonetta Sperti ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Rat Liver ◽  
Ricinus Communis ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Isolated Rat Liver ◽  
Liver Nuclei ◽  
Isolated Rat ◽  
Liver Ribosomes

1. Ricin, a toxic protein from the seeds of Ricinus communis which inhibits poly(U)-directed polyphenylalanine synthesis by rat liver ribosomes (Montanaro et al., 1973), does not affect protein synthesis by isolated rat liver mitochondria. 2. The toxin is ineffective also on poly(U)-directed polyphenylalanine synthesis in reconstituted systems with ribosomes isolated from rat liver mitochondria or from Escherichia coli. 3. Ricin inhibits protein synthesis by isolated rat liver nuclei, but at concentrations much higher than those affecting rat liver ribosomes.

scholarly journals The metabolism of L-tryptophan by isolated rat liver cells. Effect of albumin binding and amino acid competition on oxidatin of tryptophan by tryptophan 2,3-dioxygenase

1980 ◽  
Vol 186 (3) ◽  
pp. 977-986 ◽  
Author(s):  
S A Smith ◽  
C I Pogson
Keyword(s):  
Amino Acids ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Albumin Binding ◽  
Isolated Rat Liver ◽  
Free Tryptophan ◽  
Rat Liver Cells ◽  
Tryptophan Oxidation ◽  
Isolated Rat

1. Novel methods, using L-[ring-2-14C]tryptophan, are described for the measurement of tryptophan 2,3-dioxygenase activity and tryptophan accumulation in isolated rat liver cells. 2. The effects of bovine serum albumin, non-esterified fatty acids and neutral amino acids on tryptophan oxidation by hepatocytes and on the partition of tryptophan between free and albumin-bound forms were investigated. 3. Oxidation of physiological concentrations (0.1 mM) of tryptophan was inhibited by approx. 50% in the presence of 2% (w/v) bovine serum albumin; no effects were found at tryptophan concentrations of 0.5 mM and above. 4. Increases in free tryptophan concentrations produced by displacement of 0.1 mM-tryptophan from albumin-binding sites by palmitate resulted in increased flux through tryptophan dioxygenase. 5. Addition of a mixture of neutral amino acids, at plasma concentrations, to hepatocyte incubations had no effect on the rate of tryptophan oxidation. 6. It is concluded that alterations in free tryptophan concentrations consequent to changes in albumin binding may be an important factor in regulating tryptophan uptake and catabolism by the liver. The results are briefly discussed with reference to possible consequences on brain tryptophan metabolism.

Transport of the aromatic amino acids into isolated rat liver cells by a ‘T’ system

1985 ◽  
Vol 13 (4) ◽  
pp. 693-694
Author(s):  
MARK SALTER ◽  
RICHARD G. KNOWLES ◽  
CHRISTOPHER I. POGSON
Keyword(s):  
Amino Acids ◽  
Rat Liver ◽  
Aromatic Amino Acids ◽  
Liver Cells ◽  
Isolated Rat Liver ◽  
Rat Liver Cells ◽  
Isolated Rat ◽  
T System
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