Depolarization of human neuroblastoma cells as a result of muscarinic receptor‐induced rise in cytosolic Ca 2+
1989; Wiley; Volume: 242; Issue: 2 Linguagem: Inglês
10.1016/0014-5793(89)80497-1
ISSN1873-3468
Autores Tópico(s)Neuroscience and Neuropharmacology Research
ResumoThe role of intracellular free Ca 2+ in muscarinic‐receptor linked depolarization of SH‐SY5Y neuroblastoma cells has been determined by using the bisoxonol membrane potential probe DiBaC 4 −(3) and intracellular Ca 2+ indicator fura‐2‐respectively. Carbachol and the Ca 2+ ionophore, ionomycin, at concentrations which caused similar rises in intracellular Ca 2+ increased the bisoxonol fluorescence (depolarization) to the same extent. The membrane potential responses, but not the changes in intracellular Ca 2+ , were dependent on extracellular Na + . Ionomycin depletion of intracellular Ca 2+ with EGTA and ionomycin or loading the cells with a Ca 2+ buffer, BAPTA, reduced the carbachol‐induced depolarization. The results suggest that a rise in intracellular Ca 2+ may cause depolarization through an increase in the Na + permeability.
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