help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS

Biophysical Journal 64: 1323-1330 (1993)
© 1993 the Biophysical Society

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Shen, J
Right arrow Articles by Dewey, C F
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shen, J
Right arrow Articles by Dewey, C F, Jr

Regulation of adenine nucleotide concentration at endothelium-fluid interface by viscous shear flow.

J Shen, M A Gimbrone, Jr, F W Luscinskas and C F Dewey, Jr

Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge 02139.

ABSTRACT

The action of adenine nucleotides on vascular endothelial cells is apparently mediated by the local flow conditions. Because nucleotides are sequentially degraded from ATP-->ADP-->AMP-->adenosine by ecto-enzymes at the endothelial surface, it has been hypothesized that the observed flow effect is caused by the flow-dependent change of nucleotide concentration at the cell surface. In this study, we have calculated the concentration profiles of adenine nucleotides at the cell surface under flow conditions encountered in an in vitro parallel-plate flow system, as has been used in several related experimental studies. When medium containing uniformly distributed ATP is perfused over endothelial monolayers, our results show that ATP concentration in the cell vicinity gradually decreases in the streamwise direction as a result of enzymatic degradation. This hydrolysis of ATP results in the generation of ADP, and ADP concentration in turn gradually increases at the cell surface. The concentration profiles of nucleotides are dependent on the levels of applied wall shear rate. As the corresponding shear stress increases from 0.1 to 30 dynes/cm2, ATP concentration at the cell surface at the center of coverslip increases from 0.66 to 0.93. Under no-flow conditions, our model predicts a steady decline of ATP concentration and a transient increase of ATP-derived ADP, comparable to the published results of previous experiments. These numerical results, combined with our recent experimental data, provide insights into the cellular mechanisms by which hemodynamic flow modulates the effects of vasoactive agents on endothelium.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1993 by the Biophysical Society.