Protein-catabolic stage of isolated rat hepatocytes.
Isolated rat hepatocytes in suspension are in a protein-catabolic state (negative nitrogen balance), as measured by the continuous release of nitrogen in the form of amino acids and urea. The nitrogen loss corresponds to a protein degradation rate of 3-4% per h, while the rate of protein synthesis is negligible. Cells prepared from fasted, fed to regenerating livers are all highly protein-catabolic. The nitrogen balance is unaffected by insulin or amino acids (physiological mixture), and various metabolites and sera have only moderate effects. However, incubation of the cells for 2-4 h in a tissue culture medium (Dulbecco's) reduces the nitrogen loss dramatically, suggesting the formation of an anticatabolic factor under these conditions.
D000596:Amino Acids / Q000378:metabolism*; D000641:Ammonia / Q000096:biosynthesis; D000818:Animals; D003470:Culture Media; D003513:Cycloheximide / Q000494:pharmacology; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D009584:Nitrogen / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D014508:Urea / Q000096:biosynthesis
D000596:Amino Acids; D003470:Culture Media; D011506:Proteins; D000641:Ammonia; D014508:Urea; D003513:Cycloheximide; D009584:Nitrogen