Gap junction channel gating and permselectivity: their roles in co-ordinated tissue function.

1. The gating and permselective properties of gap junction channels are important parameters to determine in delineating their role in co-ordinated tissue function. This is of particular relevance in non-excitable tissues. 2. In the present study gating characteristics of rCx43 are demonstrated. The mean open times are of the order of 0.45-1.1 s. These values are extraordinarily large. 3. The permselectivity of a variety of gap junction channels is also illustrated to show the poor selectivity properties of gap junctions and, hence, their potential to allow the permeation of second messenger molecules. 4. Gating and permselectivity, along with diffusion modelling, produce a picture for gap junction channels that is consistent with physiologically relevant modulation or regulation of gap junction channel patency.