Significant contribution of liver nonparenchymal cells to metabolism of ammonia and lactate and cocultivation augments the functions of a bioartificial liver
| Autor: | Arthur Revhaug, Bård Smedsrød, Ole-Martin Fuskevåg, Ingvild Pettersen, Lars M. Ytrebø, Kjell Bertheussen, Bodil Langbakk, Kjetil Elvevold, Geir I. Nedredal |
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| Rok vydání: | 2007 |
| Předmět: |
Male
medicine.medical_specialty Arginine Physiology Liver cytology Sus scrofa Biology law.invention chemistry.chemical_compound Oxygen Consumption Glutaminase Ammonia law Physiology (medical) Internal medicine otorhinolaryngologic diseases medicine Animals Lactic Acid Amino Acids Hepatology Gastroenterology Bioartificial liver device Metabolism Ornithine Liver Artificial Coculture Techniques Glutamine stomatognathic diseases Endocrinology Liver chemistry Hepatocytes Liver function Metabolic Networks and Pathways |
| Zdroj: | American Journal of Physiology-Gastrointestinal and Liver Physiology. 293:G75-G83 |
| ISSN: | 1522-1547 0193-1857 |
| DOI: | 10.1152/ajpgi.00245.2006 |
| Popis: | A bioartificial liver (BAL) will bridge patients with acute liver failure (ALF) to either spontaneous regeneration or liver transplantation. The nitrogen metabolism is important in ALF, and the metabolism of nonparenchymal liver cells (NPCs) is poorly understood. The scope of this study was to investigate whether cocultivation of hepatocytes with NPCs would augment the functions of a BAL (HN-BAL) compared with a BAL equipped with only hepatocytes (H-BAL). In addition, NPCs were similarly cultivated alone. The cells were cultivated for 8 days in simulated microgravity with serum-free growth medium. With NPCs, initial ammonia and lactate production were fivefold and over twofold higher compared with later time periods despite sufficient oxygen supply. Initial lactate production and glutamine consumption were threefold higher in HN-BAL than in H-BAL. With NPCs, initial glutamine consumption was two- to threefold higher compared with later time periods, whereas initial ornithine production and arginine consumption were over four- and eightfold higher compared with later time periods. In NPCs, the conversion of glutamine to glutamate and ammonia can be explained by the presence of glutaminase, as revealed by PCR analysis. Drug metabolism and clearance of aggregated gamma globulin, probes administered to test functions of hepatocytes and NPCs, respectively, were higher in HN-BAL than in H-BAL. In conclusion, NPCs produce ammonia by hydrolysis of amino acids and may contribute to the pathogenesis of ALF. High amounts of lactate are produced by NPCs under nonhypoxic conditions. Cocultivation augments differentiated functions such as drug metabolism and clearance of aggregated γ-globulin. |
| Databáze: | OpenAIRE |
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