Effect of dexamethasone on gap junction intercellular communication. (A) Appearance of confluent cultures of C6 cells after iontophoresis of Lucifer Yellow in one single cell (*) in the absence (left) or presence (right) of dexamethasone (DEX). Photomicrographs are representative of the typical appearance of such injected cells. (B) FACS analysis of calcein dye transfer between rat C6 cells in the presence (right) or absence (left) of DEX. The GJIC is directly correlated with the percentage of CMTMR+/Calcein+ cells (upper right quadrants, see text for details). This experiment is representative of 3 independent experiments each performed on 10,000 cells. A Western blot of Cx43 in C6 cells is shown (left: control conditions, right, DEX treatment. See text for details) (C) FACS analysis of calcein dye transfer between human U87 (above) and LN18 (below) cells in the presence (right) or absence (left) of DEX. The rightmost pictures illustrate the basal GJIC of both cell types in confluent cultures after iontophoresis of Lucifer Yellow in a single cell (*, control conditions).