Inositol 1,4,5-trisphosphate and basal Ca2+ release is affected by the cytoplasmic concentration of Cl- in endothelial cells.
The effects of varying Cl- concentration in the intracellular bathing medium, on IP3-induced 45Ca2+ release from internal stores, were examined in saponin-permeabilised bovine aortic endothelial (BAE) cells. Results from this study show that the release of Ca2+ from the internal stores is affected by the cytoplasmic concentration of Cl- ions. Complete replacement of Cl- with gluconate augmented IP3 (3 microM)-induced 45Ca2+ release by 33 +/- 8%. Replacement of both Cl- and K+ with gluconate and NMG, respectively, had no significant effect on 45Ca2+ release. However, resting levels of internal 45Ca2+ were found to be affected by Cl- removal. These data suggest that in BAE cells, IP3 and also basal 45Ca2+ release may be regulated by the physiological intracellular Cl- concentration.
Wood
P G
PG
Department of Physiological Sciences, Medical School, University, Framlington Place, Newcastle upon Tyne, NE2 4HH, United Kingdom. P.G.Wood@newcastle.ac.uk
Gillespie
J I
JI
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D002712:Chlorides / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism*; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*
D002712:Chlorides; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium