Cell volume changes affect gluconeogenesis in the perfused liver of the catfish Clarias batrachus

Journal of biosciences

Carina Goswami¹  Nirmalendu Saha1¹  Shritapa Datta¹  Kuheli Biswas¹ 

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

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

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

In addition to lactate and pyruvate, some amino acids were found to serve as potential gluconeogenic substrates in the perfused liver of Clarias 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 hyper-osmotically 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 in C. batrachus in maintaining glucose homeostasis, which is influenced by cell volume changes possibly for proper energy supply under osmotic stress.

【 授权许可】

Unknown