Extracellular atp regulates transcervical permeability by
modulating two distinct paracellular pathways.
Gorodeski, George I., and James Goldfarb.
Departments of Reproductive Biology, and Physiology and Biophysics
at Case Western Reserve University School of Medicine, Cleveland,
Ohio
APStracts 3:0396C, 1996.
Extracellular ATP stimulates a biphasic change in transepithelial
electrical resistance (RTE) across cultures of human cervical
epithelial cells: an acute decrease (Phase-I), followed by a delayed
increase in resistance (Phase-II). The objective of the study was to
determine the contributions of changes in the lateral intercellular
space resistance (RLIS) and in the tight junctional resistance (RTJ)
to the changes in RTE. Phase-I and Phase-II effects were uncoupled by
treatment with BAPTA/AM, which blocks the ATP-induced increases in
cytosolic calcium, and abolishes Phase-I. BAPTA-loaded cells differed
from control cells in that: (1) Phase-I began upon adding the ATP, in
contrast to a delay of 1.5 - 3.5 min in Phase-II, (2) Phase-I
decreases in RLIS followed a simple exponential pattern, in contrast
to the complex kinetics of Phase-II, and (3) The magnitude of Phase
-II varied between 20 -100% increases in RTJ in Day 2 - 6 cultures;
the Phase-I decrease of 50% in RLIS was unrelated to different
experimental conditions. These results indicate that Phase-I and
Phase-II are induced simultaneously and independently by ATP, and
they contribute to the total changes in RTE. We conclude that ATP
-regulation of RLIS and RTJ may be important mechanisms of modulating
cervical mucus production in vivo.
Received 15 May 1996; accepted in final form 4 December 1996.
APS Manuscript Number C467-6.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996