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  • Open Access

Use of ion-channel modulating agents to study cyanobacterial Na+-K+ fluxes

Biological Procedures Online6:610137

  • Received: 18 May 2004
  • Accepted: 17 June 2004


Here we describe an experimental design aimed to investigate changes in total cellular levels of Na+ and K+ ions in cultures of freshwater filamentous cyanobacteria. Ion concentrations were measured in whole cells by flame photometry. Cellular Na+ levels increased exponentially with rising alkalinity, with K+ levels being maximal for optimal growth pH (8). At standardized pH conditions, the increase in cellular Na+, as induced by NaCl at 10 mM, was coupled by the two sodium channel-modulating agents lidocaine hydrochloride at 1 µM and veratridine at 100 µM. Both the channel-blockers amiloride (1 mM) and saxitoxin (1 µM), decreased cell-bound Na+ and K+ levels. Results presented demonstrate the robustness of well-defined channel blockers and channel-activators in the study of cyanobacterial Na+- K+ fluxes.

Indexing terms

  • Cyanobacteria
  • Sodium
  • Potassium