Endogenous somatostatin receptors mobilize calcium from inositol 1,4,5-trisphosphate-sensitive stores in NG108-15 cells

Duck Joo Rhie, Jong Ho Sung, U. Sin Ha, Hee Jung Kim, Do Sik Min, Sang June Hahn, Myung Suk Kim, Yang Hyeok Jo, Shin Hee Yoon

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Abstract

Somatostatin receptors are members of the G-protein-coupled receptor superfamily and exert their principal effects by coupling to inhibitory G-proteins. We used fura-2-based digital calcium imaging and assayed for [3H]inositol phosphates (IPs) to study the effects of somatostatin on intracellular calcium signaling in neuroblastomaXglioma NG108-15 cells. Both somatostatin-14 and octreotide induced concentration-dependent increases in intracellular Ca2+ concentration ([Ca2+]i). Thirty-four percent of the cells responded to treatment with 100 nM somatostatin-14. Somatostatin-induced responses were not blocked by the removal of extracellular calcium; instead, they were abolished by pretreatment with 100 nM thapsigargin, an agent that depletes and prevents refilling of intracellular Ca2+ stores. Pretreatment with the inositol 1,4,5-trisphosphate (IP3) receptor antagonist xestospongin C (10 μM) for 20 min inhibited markedly the somatostatin-induced response. Somatostatin (100 nM) increased [3H]IPs formation. U73122 (1 μM), an inhibitor of phospholipase C (PLC), completely blocked the somatostatin-induced [Ca2+]i increases and the formation of [3H]IPs. Pretreatment with pertussis toxin (PTX, 200 ng/ml) for 24 h blocked the somatostatin-induced responses. Thus, we conclude that activation of endogenous somatostatin receptors in NG108-15 cells induces the release of calcium from IP3-sensitive intracellular stores through PTX-sensitive G-protein-coupled PLC.

Original languageEnglish
Pages (from-to)120-128
Number of pages9
JournalBrain Research
Volume975
Issue number1-2
DOIs
Publication statusPublished - 2003 Jun 13

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All Science Journal Classification (ASJC) codes

  • Neuroscience(all)
  • Molecular Biology
  • Clinical Neurology
  • Developmental Biology

Cite this

Rhie, D. J., Sung, J. H., Ha, U. S., Kim, H. J., Min, D. S., Hahn, S. J., Kim, M. S., Jo, Y. H., & Yoon, S. H. (2003). Endogenous somatostatin receptors mobilize calcium from inositol 1,4,5-trisphosphate-sensitive stores in NG108-15 cells. Brain Research, 975(1-2), 120-128. https://doi.org/10.1016/S0006-8993(03)02596-4