A23187 causes release of inositol phosphates from cultured rat Kupffer cells.
The Ca2+ ionophore A23187 is routinely used to illustrate the extracellular Ca2+-dependence of a variety of cellular reactions. We found that A23187-induced hydrolysis of phosphoinositides to various inositol phosphates in rat Kupffer cells was accompanied by their release from the cells. The synthesis and release of inositol phosphates was A23187 concentration-dependent (0.5-10 microM), and was apparent at the lowest concentration tested. A23187-induced release of inositol phosphates increased time-dependently, was apparent at 5 s of stimulation and maximal at 20 min. The effects of A23187 were reversed by EGTA. The integrity of the cells was not affected by A23187 treatment as indicated by their exclusion of trypan blue and the lack of release of lactate dehydrogenase. We propose that such effects should be considered while evaluating the Ca2+-dependence of biological processes based on the actions of A23187.
Gandhi
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CR
Departments of Surgery and Pathology, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, E-1540 BST, 200 Lothrop Street, Pittsburgh, PA 15213, USA. GANDHICS@MSX.UPMC.EDU
Harvey
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SA
Cevallos
M
M
Olson
M S
MS
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000494:pharmacology; D007295:Inositol Phosphates / Q000378:metabolism*; D007476:Ionophores / Q000494:pharmacology*; D007728:Kupffer Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010972:Platelet Activating Factor / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D002614:Chelating Agents; D007295:Inositol Phosphates; D007476:Ionophores; D010972:Platelet Activating Factor; D000001:Calcimycin; D004533:Egtazic Acid