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Metabolites of the glycolytic pathway modulate the activity of single cardiac Na + channels
Author(s) -
Kohlhardt M.,
Fichtner H.,
Fröbe U.
Publication year - 1989
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.3.8.2542113
Subject(s) - depolarization , chemistry , patch clamp , biophysics , glycolysis , sodium channel , membrane potential , kinetics , biochemistry , sodium , biology , metabolism , physics , receptor , organic chemistry , quantum mechanics
Elementary Na + currents through single cardiac Na + channels were recorded at 19°C in patch clamp experiments with cultured neonatal rat cardiocytes. The metabolites of the glycolytic pathway, 2,3‐diphospho‐glycerate and glyceraldehyde phosphate, were identified as a novel class of modulators of Na + channel activity. In micromolar concentrations (1‐10 μmol/liter), their presence at the cytoplasmic membrane face increased the number of sequential openings during depolarization and prolonged the conductive channel state. As found after ensemble averaging, the decay kinetics of reconstructed macroscopic Na + currents became retarded and slow Na + inactivation may have been evoked. Both metabolites attenuated the rundown of channel activity that regularly develops after patch excision in the inside‐out patch configuration. It is tempting to assume that interference with Na + inactivation is the mode of action underlying the increase in single‐channel activity.—K ohlhardt , M., F ichtner , H., and F röbe , U. Metabolites of the glycolytic pathway modulate the activity of single cardiac Na + channels. FASEB J. 3: 1963‐1967; 1989.