Variations in the intracellular potentials of sub-populations of human peripheral blood mononuclear cells

Niemtzow, Richard C.; Gauci, Christopher; Serrou, B

doi:10.1007/bf00200113

Cited by 2 publications

(1 citation statement)

References 21 publications

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“…A better estimate of the resting membrane potential is the peak potential (Ep), which is reached within the first milliseconds after microelectrode entry. Measurements of Eo showed that the true membrane potential of macrophages can be at least a factor two to three times more negative than has been presumed on the basis of sustained potential recordings, reported by others (1,11,12,15,16). The result of general interest for small-cell electrophysiology is the demonstration (by two-electrode impalements) that Lassen's interpretation (21,22) of the initial fast peak transient upon impalement is essentially correct and that, therefore, his analysis can be used to evaluate the role of leakage during microelectrode measurements.…”

Section: Discussionmentioning

confidence: 99%

Estimation of the membrane potential of cultured macrophages from the fast potential transient upon microelectrode entry

İnce¹,

Ypey²,

Furth³

et al. 1983

The Journal of Cell Biology

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Analysis of membrane potential recordings upon microelectrode impalement of four types of macrophages (cell lines P388DI and PU5-1.8, cultured mouse peritoneal macrophages, and cultured human monocytes) reveals that these cells have membrane potentials at least two times more negative than sustained potential values (Es) frequently reported. Upon microelectrode entry into the cell (P388DI), the recorded potential drops to a peak value (Ep) (mean -37 rnV for 50 cells, range -15 to -70 mV) within 2 ms, after which it decays to a depolarized potential (En) (mean -12 mV) in about 20 ms. Thereafter, the membrane develops one or a series of slow hyperpolarizations before a final sustained membrane potential (Es) (mean -14 mV, range -5 to -40) is established. The mean value of the peak of the first hyperpolarization (Eh) is --30 mV (range -10 to -55 mV). The initial fast peak transient, measured upon microelectrode entry, was first described and analyzed by Lassen et al. (Lassen, U. V., A. M. T. Nielson, L. Pape, and L. O. Simonsen, 1971, J. Membr. Biol. 6:269-288) for other cells. It indicates that the microelectrode introduces a leakage into the membrane, causing a change in the membrane potential from its real value before impalement to a sustained depolarized value. This was shown to be true for macrophages by two-electrode impalements of single cells. Values of Ep, E,, Eh, Es, and membrane resistance (Rm) measured for the other macrophages were similar to those of P388DI. From these results we conclude that Eo is a better estimate of the true membrane potential of macrophages than Es, and that the slow hyperpolarizations upon impalement should be regarded as transient repolarizations back to the original membrane potentials. Thus, analysis of the initial fast impalement transient can be a valuable aid in the estimation of the membrane potential of various sorts of small isolated cells by microelectrodes.

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Section: Discussionmentioning

confidence: 99%