Ammonia overloading in hepatocytes isolated from liver of fetal and adult rats

• Published in: Biochimica et biophysica acta Vol. 586; no. 3; pp. 481 - 491
• Main Authors: Chico, Enrique, Olavarría, Jesús S., Núñez De Castro, Ignacio
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 03.09.1979
• Subjects: Alanine - biosynthesis; Amino acid synthesis; Aminooxyacetic Acid - pharmacology; Ammonia - pharmacology; Ammonia detoxification; Ammonia overloading; Animals; Aspartic Acid - biosynthesis; Female; Fructose - metabolism; Glucose - metabolism; Glutamates - biosynthesis; Lactate production; Lactates - metabolism; Liver - drug effects; Liver - embryology; Liver - metabolism; Pregnancy; Rats; Urea - biosynthesis; Urea cycle; Urea cycle; Ammonia detoxification; Ammonia overloading; Amino acid synthesis; Lactate production
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/0304-4165(79)90038-2

Ammonia overloading was investigated during glucose and fructose metabolism in isolated hepatocytes under a variety of metabolic conditions. In all assay conditions, the glycolytic flux and oxygen uptake was not modified by 10 mM ammonia. In hepatocytes isolated from rats fed as libitum, the presence of ammonia caused a decrease in the production of lactate (pyruvate); this effect was not observed in anaerobic incubations, in hepatocytes isolated from starved animals, or in fetal hepatocytes. In spite of an overproduction of urea, ammonia detoxification also takes place by the synthesis of alanine, glutamate and aspartate. Addition of 1 mM aminooxyacetate, an inhibitor of aminotransferases, to the incubation medium prevents the formation of these amino acids, and also prevents the decrease of lactate in hepatocytes isolated from fed animals.