This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.106.100685v1 93/9/3026    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 Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Tada, S. Articles by Tarbell, J. M. Search for Related Content PubMed PubMed Citation Articles by Tada, S. Articles by Tarbell, J. M.

Effect of the Stress Phase Angle on the Strain Energy Density of the Endothelial Plasma Membrane

Shigeru Tada ^*, Cheng Dong  and John M. Tarbell 

^* Department of Applied Physics, National Defense Academy, Yokosuka City, Japan; Department of Bioengineering, The Pennsylvania State University, University Park, Pennsylvania; and Department of Biomedical Engineering, The City College of New York/City University of New York, New York, New York

Correspondence: Address reprint requests to John M. Tarbell, Tel.: 212-650-6841; E-mail: tarbell{at}ccny.cuny.edu.

Endothelial cells are simultaneously exposed to the mechanical forces of fluid wall shear stress (WSS) imposed by blood flow and solid circumferential stress (CS) induced by the blood vessel's elastic response to the pressure pulse. Experiments have demonstrated that these combined forces induce unique endothelial biomolecular responses that are not characteristic of either driving force alone and that the temporal phase angle between WSS and CS, referred to as the stress phase angle, modulates endothelial responses. In this article, we provide the first theoretical model to examine the combined forces of WSS and CS on a model of the endothelial cell plasma membrane. We focus on the strain energy density of the membrane that modulates the opening of ion channels that can mediate signal transduction. The model shows a significant influence of the stress phase angle on the strain energy density at the upstream and downstream ends of the cell where mechanotransduction is most likely to occur.