Bombesin-evoked gastrin release and calcium signaling in human antral G cells in culture

Squires, Paul E. and Meloche, R. M. and Buchan, A. M. J. (1999) Bombesin-evoked gastrin release and calcium signaling in human antral G cells in culture. American Journal of Physiology - Gastrointestinal and Liver Physiology, 276 (1 39-1). G227-G237. ISSN 0193-1857

Full content URL: http://ajpgi.physiology.org/content/276/1/G227

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Bombesin-evoked gastrin release and calcium signaling in human antral G cells in culture

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Abstract

Amplification of mRNA from a human antral cell culture preparation demonstrated the presence of two receptors of the bombesin and gastrin- releasing peptide family, GRPR-1 and BRS-3. Single cell microfluorometry demonstrated that most cells that exhibited bombesin-evoked changes in intracellular Ca2+ concentration were gastrin immunoreactive, indicating that antral G cells express the GRPR subtype. There were two components to the intracellular Ca2+ response: an initial nitrendipine-insensitive mobilization followed by a sustained phase that was inhibited by removal of extracellular Ca2+ and 20 mM caffeine and was partially inhibited by 10 μM nitrendipine. Preexposure of cells to thapsigargin and caffeine prevented the response to bombesin, indicating activation of inositol 1,4,5-trisphosphate (IP3)-sensitive stores. Gastrin release could be partially reversed by removal of extracellular Ca2+ and blockade of L-type voltage-dependent Ca2+ channels, indicating that a component of the secretory response to bombesin was dependent on Ca2+ influx. These data demonstrated that bombesin-stimulated gastrin release from human antral G cells resulted from activation of GRPRs and involved both release of intracellular Ca2+ and influx of extracellular Ca2+ through a combination of L-type voltagegated and IP3-gated Ca2+ channels.

Keywords:bombesin, calcium ion, gastrin, article, calcium cell level, calcium mobilization, cell membrane transport, controlled study, gastrin cell, gastrin release, human, human cell, priority journal, protein expression, signal transduction, Adolescent, Adult, Calcium, Calcium Signaling, Cells, Cultured, Cytosol, Gastrins, Humans, Immunohistochemistry, Middle Aged, Pyloric Antrum, Receptors, Bombesin, Reverse Transcriptase Polymerase Chain Reaction
Subjects:C Biological Sciences > C990 Biological Sciences not elsewhere classified
Divisions:College of Science > School of Life Sciences
ID Code:14355
Deposited On:18 Jun 2014 15:45

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