Glucose-induced pulsatile insulin release from single islets at stable and oscillatory cytoplasmic Ca2+
Glucose-induced pulsatile insulin release from single islets at stable and oscillatory cytoplasmic Ca2+
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DOI：
10.1152/ajpendo.1998.274.5.e796
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发表时间：
1998-05-01
影响因子：
5.1
通讯作者：
Bergsten, P
中科院分区：
文献类型：
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作者：
Bergsten, P
在培养过夜的小鼠胰岛中同时测量细胞质 Ca2+ 浓度 ([Ca2+](i)) 和胰岛素释放。在 3 mM 葡萄糖条件下，[Ca2+](i) 为 105 nM，胰岛素释放量为 3 pmol.g(-1).s(-1)。葡萄糖浓度增加至 7 mil 时，[Ca2+](i) 会短暂减少，而胰岛素释放量会加倍，并且以 0.47 min(-1) 的频率出现脉动。 [Ca2+](i) 在 11 mM 葡萄糖时出现相似频率的振荡，与胰岛素振荡幅度增加相关，使分泌率提高 10 倍。在 16 和 20 mM 葡萄糖存在下，[Ca2+](i) > 300 nM，并且除了两个胰岛外没有显示任何振荡，这表明 [Ca2+](i) 在 16 mM 葡萄糖下存在小幅度振荡。保持频率的胰岛素释放分别增加 46% 和 31%。当葡萄糖浓度从 3 mM 增加到 11 mM 时，[Ca2+](i) 下降，其最低点出现的时间明显早于葡萄糖浓度从 3 mM 增加到 7 mM 时。葡萄糖诱导的孤立胰岛胰岛素释放在稳定和振荡 [Ca2+](i) 下都是脉动的，当 [Ca2+](i) 不变时，糖也会引起分泌速率的变化。
The cytoplasmic Ca2+ concentration ([Ca2+](i)) and insulin release were measured simultaneously in mouse pancreatic islets cultured overnight. [Ca2+](i) was 105 nM and insulin release 3 pmol.g(-1).s(-1) at 3 mM glucose. An increase to 7 mil glucose reduced [Ca2+](i) transiently, whereas insulin release doubled and was pulsatile with a frequency of 0.47 min(-1). [Ca2+](i) oscillations with similar frequency appeared at 11 mM glucose associated with increased amplitude of the insulin oscillations, raising the secretory rate 10-fold. In the presence of 16 and 20 mM glucose [Ca2+](i) was > 300 nM and showed no oscillations apart from two islets, which demonstrated [Ca2+](i) oscillations with small amplitude at 16 mM glucose. Insulin release with maintained frequency increased by 46 and 31% respectively. When the glucose concentration was increased from 3 to 11 mM, [Ca2+](i) decreased with a nadir that appeared significantly earlier than when the glucose concentration was raised from 3 to 7 mM. Glucose-induced insulin release from the isolated islet is pulsatile both at stable and oscillatory [Ca2+](i), with changes in secretory rate caused by the sugar also when [Ca2+](i) is unchanged.