Reversible effects of heptanol on gap junction structure and cell-to-cell electrical coupling.

It has been shown that certain alkanols such as heptanol and octanol reversibly uncouple crayfish axons. We have studied the effects of heptanol on the electrical coupling in Xenopus embryo cells and on the gap junction particle distribution of stomach and pancreas epithelia. Cell-to-cell electrical communication in Xenopus embryos reversibly decreases 10-15 min after the beginning of heptanol superfusion to reach values of coupling ratio lower than 0.05. Particle density of rat stomach and pancreas gap junction reversibly increases after exposure to heptanol-Tyrode's solutions. In stomach, gap junction particles from isles with hexagonal patterns after 10 to 15 min; in pancreas crystallization occurs after 20 to 30 min. Optical diffractions are used to average particle spacings in treated and control junctions of pancreas.