Diversity and regulation of amiloride-sensitive Na+ channels

Academic Article

Abstract

  • Amiloride-sensitive Na+ channels play a vital role in many important physiological processes such as delineation of the final urine composition, sensory transduction, and whole-body Na+ homeostasis. These channels display a wide range of biophysical properties, and are regulated by cAMP-mediated second messenger systems. The first of these channels has recently been cloned. This cloned amiloride-sensitive Na+ channel is termined ENaC (Epithelial Na+ Channel) and, in heterologous cellular expression systems, displays a single channel conductance of 4 to 7 pS, a high P(Na)/P(K) (> 10), a high amiloride sensitivity (K(i)(amil) = 150 nM), and relatively long open and closed times. ENaC may form the core conduction element of many of these functionally diverse forms of Na+ channel. The kinetic and regulatory differences between these channels may be due, in large measure, to unique polypeptides that associate with the core element, forming a functional channel unit.
  • Digital Object Identifier (doi)

    Author List

  • Benos DJ; Awayda MS; Berdiev BK; Bradford AL; Fuller CM; Senyk O; Ismailov II
  • Start Page

  • 1632
  • End Page

  • 1637
  • Volume

  • 49
  • Issue

  • 6