This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.107.114611v1 94/6/2043    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Vajrala, V. Articles by Miller, J. H. PubMed PubMed Citation Articles by Vajrala, V. Articles by Miller, J. H., Jr.

Effects of Oscillatory Electric Fields on Internal Membranes: An Analytical Model

Vijayanand Vajrala ^*, James R. Claycomb ^* , Hugo Sanabria ^*  and John H. Miller, Jr. ^*

^* Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, Texas; Department of Mathematics and Physics, Houston Baptist University, Houston, Texas; and University of Texas Health Science Center, Houston, Texas

Correspondence: Address reprint requests to James. R. Claycomb, E-mail: jclaycomb{at}hbu.edu.

We derive an analytical model of the potential differences induced across plasma and internal organelle membranes in suspended cells exposed to oscillatory electric fields. Multiple shells are modeled using iterative applications of the single-shell calculation with mobile charges. This work is motivated, in part, by recent results suggesting the ability to use alternating current (ac) fields to noninvasively monitor enzyme activity within internal membranes, particularly the mitochondrial electron transport chain. Previous work, on induced transmembrane voltages in cells subjected to ac fields, has mainly been limited to oscillatory potentials across the plasma membrane. Here we first develop a three-membrane model, consisting of a plasma membrane surrounding inner and outer membranes representing an internal organelle, such as a mitochondrion. Frequency-dependent transmembrane potentials are modeled for spherical, weakly conducting membrane shells enclosing a conductive cytoplasm surrounding an idealized internal organelle. We then use a two-shell model to simulate induced ac membrane potentials of a suspended isolated mitochondrion in which the outer membrane is usually much more permeable than the inner membrane.