Flow- and bradykinin-induced nitric oxide production by endothelial
cells is independent of membrane potential.
Gooch, Keith J., and John A. Frangos.
Department of Chemical Engineering, The Pennsylvania State
University, University Park, PA 16802 and Department of
Bioengineering, University of California - San Diego, La Jolla, CA
92093
APStracts 2:0328C, 1995.
The objective of this study was to evaluate the role transmembrane
potential plays in flow-induced nitric oxide (NO) production in
endothelial cells (EC). NO production was monitored by measuring
intracellular guanosine 3',5'-cyclic monophosphate (cGMP) and
extracellular NOx (NO2- + NO3-). Primary human umbilical vein
endothelial cells (HUVEC) were exposed to laminar flow (22 dyn / cm2)
of media with 5.4 mM KCl (control media) with or without 3 mM
tetraethylammonium chloride (TEA) or 90 mM KCl (K+ rich media).
Bradykinin (BK) was added to time matched stationary cultures to give
a final concentration of 5 nM. With control media, 30 seconds, 2
minutes and 3 hours of treatment with flow or 2 minutes of treatment
with BK resulted in approximately a 3-fold increase in cGMP over
stationary cultures. Depolarization with KCl or TEA did not influence
cGMP production in flow-treated or stationary cultures. Flow of
either control or potassium-rich media resulted in approximately a
10-fold increase in average NOx production rate over three hours
compared to stationary cultures. Taken together these data indicate
that neither membrane hyperpolarization nor normal membrane potential
is necessary for flow- or BK- induced NO production by HUVEC.
Received 24 February 1995; accepted in final form 8 August 1995.
APS Manuscript Number C103-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 September 1995.