title: Single-channel currents in isolated patches of plasma membrane from basal surface of pancreatic acini.
abstract: Precise localization and characterization of conductance pathways in glandular epithelia have so far proved difficult. The patch-clamp technique for high resolution current recording, which has already been applied successfully to a number of electrically excitable cells, can in principle overcome these difficulties. We now report measurements of single-channel currents from isolated patches of plasma membrane (inside-out) from the baso-lateral surface of collagenase-isolated rat and mouse pancreatic acini. We have identified a cation channel having a conductance of approximately 30 pS and a mean open time in the range 0.3-1 s which is dependent on internal calcium. The single-channel current-voltage relationship is linear and the mean open time independent of the membrane potential. These channels may, at least in part, account for the Ca2+-mediated neural and hormonal control of pancreatic acinar membrane conductance, which is probably responsible for the Ca2+-dependent acinar fluid secretion.
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000502:physiology*; D066298:In Vitro Techniques; D007473:Ion Channels / Q000502:physiology*; D008564:Membrane Potentials; D051379:Mice; D010179:Pancreas / Q000166:cytology* / Q000502:physiology; D051381:Rats
chemical_list: D007473:Ion Channels; D002118:Calcium