Osmolytes and Mechanisms Involved in Regulatory Volume Decrease under Conditions of Sudden or Gradual Osmolarity Decrease

Benito Ordaz, Karina Tuz, Lenin D. Ochoa, Ruth Lezama, Claudia Peña-Segura, Rodrigo Franco

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24 Scopus citations


A decrease in external osmolarity results in cell swelling and the immediate activation of a mechanism to restore cell volume, known as regulatory volume decrease (RVD). When exposed to a gradual osmolarity decrease (GODE), some cells do not swell. This reflects the operation of an active regulatory process known as isovolumetric regulation (IVR). The mechanisms underlying IVR appear similar to those activated during RVD, namely the extrusion of K +, Cl-, amino acids, and other organic molecules. A previous study has documented IVR in cerebellar granule neurons, parallel to an early efflux of taurine and Cl-, whereas K+ efflux is delayed. In this work we briefly review the importance of amino acids in the mechanisms of cell volume control in the brain, with emphasis on IVR. We also present experiments showing the response to GODE in cerebellar astrocytes. The currents activated during GODE, recorded in the whole-cell configuration of the patch clamp technique, indicate the early activation of an anion current, followed by a more delayed cation current. A correlation between the time course of amino acid efflux during GODE and the occurrence or not of IVR in various cell types, suggest the importance of these osmolytes in the volume regulatory process in this model.

Original languageEnglish (US)
Pages (from-to)65-72
Number of pages8
JournalNeurochemical Research
Issue number1
Publication statusPublished - Jan 1 2004



  • Astrocytes
  • Isovolumetric regulation
  • Osmolytes
  • Swelling
  • Taurine
  • Volume regulation

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

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