Endocrine Journal | |
Synergistic Insulin Release Induced by Glucose and Carbachol is not associated with an Increase in Cytoplasmic Free Calcium Levels | |
JUNICHIRO KASHIWADA2  KATSUHIRO TAMURA2  KEIICHIRO TANIGAWA1  YUZURU KATO1  | |
[1] Internal Medicine, Shimane Medical University;Departments of Surgery, Shimane Medical University | |
关键词: Insulin release; Ca2+; Fura-2; Phosphoinositide breakdown; | |
DOI : 10.1507/endocrj.41.677 | |
学科分类:内分泌与代谢学 | |
来源: Japan Endocrine Society | |
【 摘 要 】
References(24)Synergistic insulin release is observed in combination with muscarinic agonist and glucose. In order to define the role of changes in the cytoplasmic free Ca2+level ([Ca2+] i), the effect of combination with carbachol and glucose on both phosphoinositide breakdown in rat pancreatic islets and [Ca2+] i dynamics in single fura 2-loaded B-cells was investigated. When the islets were prelabeled with myo-[2-3H] inositol, phosphoinositide breakdown was obtained and inositol trisphosphate levels were increased in the presence of carbachol (0.5 mM). Inositol trisphosphate levels induced by carbachol were further increased by co-stimulation with 16.7 mM glucose.[Ca2+] i in single-B-cells was increased by 16.7 mM glucose. A prompt, transient rise in [Ca2+] i was induced by carbachol. However, carbachol failed to augment the [Ca2+] i response in the presence of 16.7 mM glucose. These data suggest that a synergistic release of insulin occurs without an amplification of [Ca2+] i regardless of an increase in inositol trisphosphate.
【 授权许可】
Unknown
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