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. + + + + +
  • Published In

    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