Huang L, Shen H, Atkinson M A, Kennedy R T
Department of Chemistry, University of Florida, Gainesville 32611, USA.
Proc Natl Acad Sci U S A. 1995 Oct 10;92(21):9608-12. doi: 10.1073/pnas.92.21.9608.
Amperometry at a carbon fiber microelectrode modified with a composite of ruthenium oxide and cyanoruthenate was used to monitor chemical secretions of single pancreatic beta cells from rats and humans. When the insulin secretagogues glucose, tolbutamide, and K+ were applied to the cell, a series of randomly occurring current spikes was observed. The current spikes were shown to be due to the detection of chemical substances secreted from the cell. Chromatography showed that the primary secreted substance detected by the electrode was insulin. The current spikes were strongly dependent on external Ca2+, had an average area that was independent of the stimulation method, and had an area distribution which corresponded to the distribution of vesicle sizes in beta cells. It was concluded that the spikes were due to the detection of concentration pulses of insulin secreted by exocytosis.
使用氧化钌和氰基钌酸盐复合物修饰的碳纤维微电极进行安培测量，以监测大鼠和人类单个胰腺β细胞的化学分泌物。当向细胞施加胰岛素促分泌剂葡萄糖、甲苯磺丁脲和K⁺时，观察到一系列随机出现的电流尖峰。这些电流尖峰表明是由于检测到细胞分泌的化学物质所致。色谱分析表明，电极检测到的主要分泌物质是胰岛素。电流尖峰强烈依赖于外部Ca²⁺，其平均面积与刺激方法无关，且面积分布与β细胞中囊泡大小的分布相对应。得出的结论是，这些尖峰是由于检测到通过胞吐作用分泌的胰岛素浓度脉冲所致。
