Apparent intracellular Mg2+ buffering in neurons of the leech Hirudo medicinalis.
Research article published in Biophysical journal (2001)
Abstract
The apparent intracellular Mg2+ buffering, or muffling (sum of processes that damp changes in the free intracellular Mg2+ concentration, [Mg2+](i), e.g., buffering, extrusion, and sequestration), was investigated in Retzius neurons of the leech Hirudo medicinalis by iontophoretic injection of H+, OH-, or Mg2+. Simultaneously, changes in intracellular pH and the intracellular Mg2+, Na+, or K+ concentration were recorded with triple-barreled ion-selective microelectrodes. Cell volume changes were monitored measuring the tetramethylammonium (TMA) concentration in TMA-loaded neurons. Control measurements were carried out in electrolyte droplets (diameter 100-200 microm) placed on a silver wire under paraffin oil. Droplets with or without ATP, the presumed major intracellular Mg2+ buffer, were used to quantify the pH dependence of Mg2+ buffering and to determine the transport index of Mg2+ during iontophoretic injection. The observed pH dependence of [Mg2+](i) corresponded to what would be expected from Mg2+ buffering through ATP. The quantity of Mg2+ muffling, however, was considerably larger than what would be expected if ATP were the sole Mg2+ buffer. From the decrease in Mg2+ muffling in the nominal absence of extracellular Na+ it was estimated that almost 50% of the ATP-independent muffling is due to the action of Na+/Mg2+ antiport.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
The apparent intracellular Mg2+ buffering, or muffling (sum of processes that damp changes in the free intracellular Mg2+ concentration, [Mg2+](i), e.g., buffering, extrusion, and sequestration), was investigated in Retzius neurons of the leech Hirudo medicinalis by iontophoretic injection of H+,...
Por qué esto importa para la hirudoterapia
Este estudio investigó los mecanismos de tamponamiento intracelular de Mg2+ en las neuronas de Retzius de la sanguijuela Hirudo medicinalis mediante microelectrodos selectivos de iones e inyecciones iontoforéticas, encontrando que el tamponamiento dependiente de ATP explica la dependencia del pH observada, mientras que aproximadamente el 50% del tamponamiento independiente de ATP es atribuible a la actividad del antiportador Na+/Mg2+. Para el dominio de ASH, este artículo utiliza Hirudo medicinalis —la misma especie central en la hirudoterapia— como organismo modelo para investigación básica en neurociencia. Sin embargo, el estudio examina la fisiología celular fundamental de las neuronas de la sanguijuela sin conexión con aplicaciones terapéuticas, el secretoma de la sanguijuela ni la hirudoterapia clínica. Su relevancia se limita a aportar conocimiento biológico básico sobre la especie de sanguijuela medicinal utilizada en el campo de ASH.
Citación
Apparent intracellular Mg2+ buffering in neurons of the leech Hirudo medicinalis.
Günzel et al. · Biophysical journal, 2001
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Añadido a la biblioteca ASH: May 28, 2026 · Última actualización del sitio: 18 de junio de 2026