Ca2+ entry through reverse Na+/Ca2+ exchanger in NCI-H716, glucagon-like peptide-1 secreting cells |
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Authors: | Kyung Jin Choi Jin Wook Hwang Se Hoon Kim Hyung Seo Park |
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Affiliation: | 1.Department of Physiology, College of Medicine, Konyang University, Daejeon 35365, Korea;2.Myunggok Medical Research Institute, Konyang University, Daejeon 35365, Korea |
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Abstract: | Glucagon like peptide-1 (GLP-1) released from enteroendocine L-cells in the intestine has incretin effects due to its ability to amplify glucose-dependent insulin secretion. Promotion of an endogenous release of GLP-1 is one of therapeutic targets for type 2 diabetes mellitus. Although the secretion of GLP-1 in response to nutrient or neural stimuli can be triggered by cytosolic Ca2+ elevation, the stimulus-secretion pathway is not completely understood yet. Therefore, the aim of this study was to investigate the role of reverse Na+/Ca2+ exchanger (rNCX) in Ca2+ entry induced by muscarinic stimulation in NCI-H716 cells, a human enteroendocrine GLP-1 secreting cell line. Intracellular Ca2+ was repetitively oscillated by the perfusion of carbamylcholine (CCh), a muscarinic agonist. The oscillation of cytosolic Ca2+ was ceased by substituting extracellular Na+ with Li+ or NMG+. KB-R7943, a specific rNCX blocker, completely diminished CCh-induced cytosolic Ca2+ oscillation. Type 1 Na+/Ca2+ exchanger (NCX1) proteins were expressed in NCI-H716 cells. These results suggest that rNCX might play a crucial role in Ca2+ entry induced by cholinergic stimulation in NCI-H716 cells, a GLP-1 secreting cell line. |
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Keywords: | Calcium entry Carbamylcholine Glucagon like peptide-1 NCI-H716 Na+/Ca2+ exchanger |
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