American Society of Hirudotherapy

Apparent intracellular Mg2+ buffering in neurons of the leech Hirudo medicinalis.

Research article published in Biophysical journal (2001)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: In vitro / laboratoryGenomics & ProteomicsSalivary PharmacologyGünzel et al. · 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.

Publication typeJournal Article
Indexed MeSH termsAdenosine TriphosphateAnimalsAntiportersBuffersCell SizeGanglia, InvertebrateHydrogen-Ion ConcentrationIn Vitro TechniquesIntracellular FluidKineticsLeechesMagnesium

Summary

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+,...

Why This Matters for Hirudotherapy

This study investigated intracellular Mg2+ buffering mechanisms in Retzius neurons of the leech Hirudo medicinalis using ion-selective microelectrodes and iontophoretic injections, finding that ATP-dependent buffering accounts for the observed pH dependence while approximately 50% of ATP-independent muffling is attributable to Na+/Mg2+ antiport activity. For ASH's domain, this article uses Hirudo medicinalis — the same species central to hirudotherapy — as a model organism for basic neuroscience research. However, the study examines fundamental cell physiology of leech neurons with no connection to therapeutic applications, the leech secretome, or clinical hirudotherapy. Its relevance is limited to providing basic biological knowledge about the medicinal leech species used in ASH's field.

Citation

Apparent intracellular Mg2+ buffering in neurons of the leech Hirudo medicinalis.

Günzel et al. · Biophysical journal, 2001

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