Camp promotes gap junctional coupling in t84 cells.
Chanson, Marc, Michael M. White, and Sarah S. Garber.
Dept. of Physiology,, Medical College of Pennsylvania, and
Hahnemann University, 2900 Queen Lane, Philadelphia PA, 19129
U.S.A.
APStracts 3:0064C, 1996.
The effect of [cAMP]i on dye and electrical coupling was studied in
T84 cells, a cell line often used as a model for epithelial cell
fluid secretion. Injections of Lucifer Yellow (LY) into single cells
within a cluster control cells resulted in LY localization to 1.3 +/-
0.2 (mean +/- SEM) cells within a cluster. 26% of control T84 cell
pairs were electrically coupled as assayed by the dual patch-clamp
technique. Treatment of cells with agents that either increase
intracellular cAMP and/or activate protein kinase A (PKA) increased
dye localization to 3.8 +/- 0.6 cells and the proportion of
electrically coupled cell pairs to 65%. No electrical coupling was
observed in the presence of the PKA antagonist Rp-cAMPS. Excess of
Rp-cAMPS prevented cell coupling elicited by 20 [mu]M Sp-cAMPS.
Expression of connexin 32 mRNA, but not those for connexins 26, 43,
or 45, was detected by RT-PCR. These results suggest that
communication between T84 cells is modulated by PKA, providing a
mechanism for regulating multicellular activity, such as fluid
secretion.
Received 23 May 1995; accepted in final form 9 February 1996.
APS Manuscript Number C297-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 March 96