Na+ and Cl- conductances are controlled by cytosolic Cl- concentration in the intralobular duct cells of mouse mandibular glands

J Membr Biol. 1993 Sep;135(3):289-95. doi: 10.1007/BF00211100.


Our previously published whole-cell patch-clamp studies on the cells of the intralobular (granular) ducts of the mandibular glands of male mice revealed the presence of an amiloride-sensitive Na+ conductance in the plasma membrane. In this study we demonstrate the presence also of a Cl- conductance and we show that the sizes of both conductances vary with the Cl- concentration of the fluid bathing the cytosolic surface of the plasma membrane. As the cytosolic Cl- concentration rises from 5 to 150 mmol/liter, the size of the inward Na+ current declines, the decline being half-maximal when the Cl- concentration is approximately 50 mmol/liter. In contrast, as cytosolic Cl- concentration increases, the inward Cl- current remains at a constant low level until the Cl- concentration exceeds 80 mmol/liter, when it begins to increase. Studies in which Cl- in the pipette solution was replaced by other anions indicate that the Na+ current is suppressed by intracellular Br-, Cl- and NO3- but not by intracellular I-, glutamate or gluconate. Our studies also show that the Cl- conductance allows passage of Cl- and Br- equally well, I- less well, and NO3-, glutamate and gluconate poorly, if at all. The findings with NO3- are of particular interest because they show that suppression of the Na+ current by a high intracellular concentration of a particular anion does not depend on actual passage of that anion through the Cl- conductance. In mouse granular duct cells there is, thus, a reciprocal regulation of Na+ and Cl- conductances by the cytosolic Cl- concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amiloride / pharmacology
  • Animals
  • Biological Transport / drug effects
  • Biological Transport / physiology
  • Bromine / physiology
  • Cell Membrane / chemistry
  • Cell Membrane / physiology
  • Cell Membrane / ultrastructure
  • Chloride Channels / analysis
  • Chloride Channels / physiology*
  • Chlorides / analysis*
  • Chlorides / pharmacokinetics
  • Chlorides / physiology*
  • Cytosol / chemistry*
  • Gluconates / pharmacology
  • Glutamates / physiology
  • Male
  • Mice
  • Nitrates / physiology
  • Salivary Glands / chemistry
  • Salivary Glands / cytology*
  • Salivary Glands / physiology*
  • Sodium / pharmacokinetics
  • Sodium / physiology
  • Sodium Channels / analysis
  • Sodium Channels / physiology*


  • Chloride Channels
  • Chlorides
  • Gluconates
  • Glutamates
  • Nitrates
  • Sodium Channels
  • Amiloride
  • Sodium
  • Bromine