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    • Fulltext

       

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      Permanent link:
      https://www.ias.ac.in/article/fulltext/jbsc/029/03/0337-0347

    • Keywords

       

      Anisotonicity; cell volume; Clarias batrachus ; fructose 1,6-bisphosphatase; gluconeogenesis; glucose 6-phosphatase; hydration status; osmotic stress; phosphoenolpyruvate carboxykinase; pyruvate carboxylase

    • Abstract

       

      In addition to lactate and pyruvate, some amino acids were found to serve as potential gluconeogenic substrates in the perfused liver ofClarias batrachus. Glutamate was found to be the most effective substrate, followed by lactate, pyruvate, serine, ornithine, proline, glutamine, glycine, and aspartate. Four gluconeogenic enzymes, namely phosphoenolpyruvate carboxykinase (PEPCK), pyruvate carboxylase (PC), fructose 1,6-bisphosphatase (FBPase) and glucose 6-phosphatase (G6Pase) could be detected mainly in liver and kidney, suggesting that the latter are the two major organs responsible for gluconeogenic activity in this fish. Hypo-osmotically induced cell swelling caused a significant decrease of gluconeogenic efflux accompanied with significant decrease of activities of PEPCK, FBPase and G6Pase enzymes in the perfused liver. Opposing effects were seen in response to hyperosmotically induced cell shrinkage. These changes were partly blocked in the presence of cycloheximide, suggesting that the aniso-osmotic regulations of gluconeogenesis possibly occurs through an inverse regulation of enzyme proteins and/or a regulatory protein synthesis in this catfish. In conclusion, gluconeogenesis appears to play a vital role inC. batrachus in maintaining glucose homeostasis, which is influenced by cell volume changes possibly for proper energy supply under osmotic stress.

    • Author Affiliations

       

      Carina Goswami1 Shritapa Datta1 Kuheli Biswas1 Nirmalendu Saha1

      1. Biochemical Adaptation Laboratory, Department of Zoology, North-Eastern Hill University, Shillong - 793 022, India

    • Dates

       
      Published
      September 2004
      Manuscript received
      10 February 2004
      Manuscript revised
      14 June 2004

  • Journal of Biosciences | News

      Forthcoming Special issue.


    • To trigger further research on plant mitochondria, the Journal of Biosciences is bringing out a special issue titled "Plant Mitochondria: Properties and Interactions with Other Organelles".


      Plant mitochondria are quite distinct and have unique features, such as a cyanide-insensitive alternate pathway. They also interact with chloroplasts to optimize photosynthetic carbon assimilation.


      Submissions are welcome until 30 July 2023. The contributions can be original articles, short communications, reviews, or mini-reviews on any topic related to plant mitochondria.


      Authors can submit their articles online at https://www.editorialmanager.com/jbsc/default2.aspx

      Posted on April 12, 2023
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      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

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