Dye and electrical coupling between cells of the rabbit corneal endothelium

The corneal endothelium is known to contain gap junctions on its lateral borders. Here we show that the endothelial cells of the rabbit cornea are highly dye coupled. Lucifer Yellow CH introduced into a single cell through either an intracellular glass microelectrode or a patch electrode rapidly spreads into its neighboring cells at room temperature. We have used the analysis of Safranyos and Caveney (JCB 100:736-747, 1985) to place quantitative lower bounds on the effective diffusion coefficient of Lucifer Yellow CH iontophoresed into rabbit corneal endothelial cells. By this analysis, we obtain a value of 5.0 x 10(-8) cm2/sec. We also demonstrate that both dye and electrical coupling exists in cell pairs or small clusters of cells enzymatically dissociated from Descemet's membrane.