Direct measurement of the gap junctional conductance under the influence of Ca2+ in dissociated paired myocytes of guinea-pig.

A new method to measure the gap junctional conductance under the influence of a given pCa solution was described. The paired ventricular cells were enzymatically dissociated from the guinea pig and were voltage clamped. One of the pair was crushed to expose one aspect of the gap junction to the bath solution, which contained different pCa. The method disclosed a reversible effect of Ca closing the gap junctional channel.