...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Cellular Signalling >Protein kinase C-dependent and -independent inhibition of Ca2+ influx by phorbol ester in rat pancreatic beta-cells
【24h】

Protein kinase C-dependent and -independent inhibition of Ca2+ influx by phorbol ester in rat pancreatic beta-cells

机译：佛波醇酯对大鼠胰腺β细胞中蛋白激酶C依赖性和非依赖性Ca2 +内流的抑制

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Phorbol esters were used to investigate the action of protein kinase C (PKC) on insulin secretion from pancreatic beta -cells. Application of 80 nM phorbol 12-myristate 13-acerate (PMA). a PKC-activating phorbol ester, had little effect on glucose (15 mM)-induced insulin secretion from intact rat islets. In islets treated with bisindolylmaleimide (BIM), a PKC inhibitor, PMA significantly reduced the glucose-induced insulin secretion. PMA decreased the level of intracellular Ca2+ concentration ([Ca2+](i)) elevated by the glucose stimulation when tested in isolated rat beta -cells. This inhibitory effect of PMA was not prevented by BIM. PMA inhibited glucose-induced action potentials, and this effect was not prevented by BIM. Further, 4 alpha -phorbol 12,13-didecanoate (4 alpha -PDD), a non-PKC-activating phorbol ester, produced an effect similar to PMA. In the presence of nifedipine. the glucose stimulation produced only depolarization. and PMA applied on top of glucose repolarized the cell. When applied at the resting state. PMA hyperpolarized beta -cells with an increase in the membrane conductance. Recorded under the voltage-clamp condition. PMA reduced the magnitude of Ca2+ currents through L-type Ca2+ channels. BIM prevented the PMA inhibition of the Ca2+ currents. These results suggest that activation of PKC maintains glucose-stimulated insulin secretion in pancreatic beta -cells, defeating its own inhibition of the Ca2+ influx through L-type Ca2+ channels. PKC-independent inhibition of electrical excitability by phorbol esters was also demonstrated. (C) 2001 Published by Elsevier Science Inc. [References: 43]
机译：酚酯用于研究蛋白激酶C（PKC）对胰腺β细胞分泌胰岛素的作用。 80 nM佛波醇12-肉豆蔻酸酯13-乙酰酸酯（PMA）的应用。 PKC激活佛波酯对完整大鼠胰岛中葡萄糖（15 mM）诱导的胰岛素分泌影响很小。在用PKC抑制剂bisindolylmaleimide（BIM）处理的胰岛中，PMA显着降低了葡萄糖诱导的胰岛素分泌。在分离的大鼠β细胞中进行测试时，PMA降低了葡萄糖刺激升高的细胞内Ca2 +浓度（[Ca2 +]（i））的水平。 BIM不能阻止PMA的这种抑制作用。 PMA抑制葡萄糖诱导的动作电位，而BIM不能阻止这种作用。此外，非α-PKC活化的佛波醇酯4-α-佛波醇12，13-十二烷酸酯（4α-PDD）产生类似于PMA的作用。在硝苯地平存在下。葡萄糖刺激仅产生去极化作用。然后在葡萄糖上施加PMA，使细胞重新极化。在静止状态下使用。 PMA超极化的β细胞具有膜电导的增加。在电压钳制条件下记录。 PMA降低了通过L型Ca2 +通道的Ca2 +电流的大小。 BIM阻止了PMA抑制Ca2 +电流。这些结果表明，PKC的活化维持了胰岛β细胞中葡萄糖刺激的胰岛素分泌，从而克服了其通过L型Ca2 +通道对Ca2 +内流的抑制作用。还证实了佛波酯对PKC的电兴奋性的抑制作用。 （C）2001年由Elsevier Science Inc.出版。[参考：43]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号