Extracellular cation sensing by the enterocyte: prediction of a novel divalent cation "receptor"

Biochem Biophys Res Commun. 1995 May 25;210(3):948-53. doi: 10.1006/bbrc.1995.1748.

Abstract

We report that the divalent cation Ni2+ elicits elevations in the cytosolic free Ca2+ concentration ([Ca2+]) in cultured enterocytes. These elevations were monophasic, each response consisting of a rapid initial transient rise of cytosolic [Ca2+] to a peak value followed by an exponential decline. The magnitude of the cytosolic [Ca2+] elevation varied with the concentration of applied Ni2+. In some cells, a single application of Ni2+ induced oscillatory changes in cytosolic [Ca2+]. There was also evidence for use-dependent inactivation: a conditioning application of Ni2+ substantially attenuated the response resulting from its subsequent application. Our findings thus demonstrate the existence of a divalent cation-sensing "receptor" on the enterocyte. This putative receptor may play a role in regulating mineral absorption across the enterocyte membrane.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium / metabolism*
  • Cations, Divalent / metabolism*
  • Cell Line
  • Colon / metabolism*
  • Cytosol / metabolism
  • Epithelium / metabolism
  • Humans
  • Kinetics
  • Nickel / pharmacology*
  • Oscillometry
  • Receptors, Cell Surface / metabolism*
  • Time Factors

Substances

  • Cations, Divalent
  • Receptors, Cell Surface
  • Nickel
  • Calcium