ABSTRACT
The existence of functional gap junctions connecting pancreatic acinar cells has been demonstrated by using electric dye transfer and ultrastructural methods. This chapter discusses the gap junctions of the exocrine gland cells using the double whole-cell patch-clamp technique. Isolated pancreatic acinar cell pairs exhibit a spontaneous decrease of the junctional conductance in the double whole-cell configuration if pH- and Ca2+-buffered electrolyte solutions are used, which consist solely of electrolytes, glucose, and the pH and Ca2+ buffers. Neither the substitution of chloride nor of sodium ions in the pipette had a significant influence on spontaneous uncoupling. Also, no voltage dependence of the junctional conductance or the uncoupling time course was observed. Addition of ATP and cAMP to the pipette solution suppressed spontaneous uncoupling in pancreatic acinar cell pairs. The method to reduce the junctional conductance to the expected single-channel level is artificial uncoupling induced by long-chain alcohols as octanol.
