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    • Fulltext

       

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      Permanent link:
      https://www.ias.ac.in/article/fulltext/jbsc/037/01/0115-0123

    • Keywords

       

      Betaine; homocysteine; methylation; osmolyte

    • Abstract

       

      Betaine-homocysteine 𝑆-methyltransferase (BHMT) is an enzyme that converts homocysteine (Hcy) to methionine using betaine as a methyl donor. Betaine also acts as osmolyte in kidney medulla, protecting cells from high extracellular osmolarity. Hepatic BHMT expression is regulated by salt intake. Hormones, particularly corticosteroids, also regulate BHMT expression in rat liver. We investigated to know whether the corticoadrenal activity plays a role in kidney BHMT expression. BHMT activity in rat kidneys is several orders of magnitude lower than in rat livers and only restricted to the renal cortex. This study confirms that corticosteroids stimulate BHMT activity in the liver and, for the first time in an animal model, also up-regulate the BHMT gene expression. Besides, unlike the liver, corticosteroids in rat kidney down-regulate BHMT expression and activity. Given that the classical effect of adrenocortical activity on the kidney is associated with sodium and water re-absorption by the distal tubule leading to volume expansion, by promoting lesser use of betaine as a methyl donor, corticosteroids would preserve betaine for its other role as osmoprotectant against changes in the extracellular osmotic conditions. We conclude that corticosteroids are, at least in part, responsible for the inhibition of BHMT expression and activity in rat kidneys.

    • Author Affiliations

       

      Osvaldo Fridman1 2 3 Analía V Morales1 Laura E Bortoni2 Paula C Turk-Noceto1 Elio A Prieto1

      1. Centro de Altos Estudios en Ciencias Humanas y de la Salud, Universidad Abierta Interamericana (UAI)
      2. Instituto de Oncología Ángel H Roffo, Buenos Aires, Argentina
      3. Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina

    • Dates

       
      Published
      March 2012
      Manuscript received
      2 September 2011
      Accepted
      9 November 2011

  • 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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    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

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