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The self-referencing oxygen-selective microelectrode: detection of transmembrane oxygen flux from single cells.
- Source :
-
The Journal of experimental biology [J Exp Biol] 1999 Jan; Vol. 202 (Pt 2), pp. 211-8. - Publication Year :
- 1999
-
Abstract
- A self-referencing, polarographic, oxygen-selective microelectrode was developed for measuring oxygen fluxes from single cells. This technique is based on the translational movement of the microelectrode at a known frequency through an oxygen gradient, between known points. The differential current of the electrode was converted into a directional measurement of flux using the Fick equation. Operational characteristics of the technique were determined using artificial gradients. Calculated oxygen flux values matched theoretical values derived from static measurements. A test preparation, an isolated neuron, yielded an oxygen flux of 11.46+/-1.43 pmol cm-2 s-1 (mean +/- s.e.m.), a value in agreement with those available in the literature for single cells. Microinjection of metabolic substrates or a metabolic uncoupler increased oxygen flux, whereas microinjection of KCN decreased oxygen flux. In the filamentous alga Spirogyra greveilina, the probe could easily differentiate a 16.6% difference in oxygen flux with respect to the position of the spiral chloroplast (13.3+/-0.4 pmol cm-2 s-1 at the chloroplast and 11.4+/-0.4 pmol cm-2 s-1 between chloroplasts), despite the fact that these positions averaged only 10.6+/-1.8 microm apart (means +/- s.e.m.). A light response experiment showed real-time changes in measured oxygen flux correlated with changes in lighting. Taken together, these results show that the self-referencing oxygen microelectrode technique can be used to detect local oxygen fluxes with a high level of sensitivity and spatial resolution in real time. The oxygen fluxes detected reliably correlated with the metabolic state of the cell.
Details
- Language :
- English
- ISSN :
- 0022-0949
- Volume :
- 202
- Issue :
- Pt 2
- Database :
- MEDLINE
- Journal :
- The Journal of experimental biology
- Publication Type :
- Academic Journal
- Accession number :
- 9851909
- Full Text :
- https://doi.org/10.1242/jeb.202.2.211