ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
The electrical potential difference (PD) across the membrane of the Ehrlich mouse ascites tumor cell has been measured with intracellular microelectrodes. The mean for 111 cells in control Ringer solution was - 11.2 mV ± 0.29 (SE), interior negative. When sulfate replaced chloride in the external medium the PD fell to - 2.8 mV if measured as soon as possible after mixing the cells with a sulfate medium, but when nitrate replaced chloride the PD fell only to - 8.5 mV. Cells equilibrated in nitrate had the same PD as those in control Ringer. These results indicate that the PD is sensitive to changes in the external chloride concentration and that nitrate can substitute for chloride electrically. However, since the PD for chloride, based on the Nernst equation and calculated on the basis of 70% exchangeability of cell chloride, is three times greater than the measured PD, it is hypothesized that sodium contributes significantly to the membrane potential in addition to chloride. On the other hand, potassium does not influence the PD to any great extent.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1040690105
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