Calcium uptake by intracellular compartments in permeabilised enterocytes effect of inositol 1,4,5 trisphosphate

Research output: Contribution to journalArticle

Authors

  • Gloria Velasco
  • Stephen B. Shears
  • Bob Michell
  • Pedro S. Lazo

Colleges, School and Institutes

External organisations

  • Universidad de Oviedo
  • Birmingham University
  • Department of Biochemistry

Abstract

Treatment of rat small intestine with EDTA produced isolated enterocytes with plasma membranes which were permeable to small ions. When resuspended in a medium designed to resemble the intracellular medium, Ca2+ was accumulated into the cells. Both mitochondrial and a non-mitochondrial (presumably endoplasmic reticulum) compartments were responsible for sequestering the cation, as indicated by the effects of the mitochondrial inhibitors oligomycin and antimycin and of the Ca-ATPase inhibitor sodium orthovanadate assayed at low (0.9 μM) and high ( 12 μM) free Ca2+ concentrations. Addition of inositol (1,4,5) trisphosphate induced a rapid release of Ca2+ from the non mitochondrial compartment. The effect of inositol trisphosphate was concentration dependent and showed 50% of maximal release at 2 M. Neither cyclic AMP nor dibutryl cyclic AMP caused release of Ca2+. These findings lend novel support to the possibility that Ca-mediated control of ionic transport in the small intestine is exerted through the phosphatidylinositol-protein kinase C transduction mechanism.

Details

Original languageEnglish
Pages (from-to)612-618
Number of pages7
JournalBiochemical and Biophysical Research Communications
Volume139
Issue number2
Publication statusPublished - 16 Sep 1986