Barbosa R M, Silva A M, Tomé A R, Stamford J A, Santos R M, Rosário L M
Center for Neurosciences of Coimbra, University of Coimbra, United Kingdom.
Biochem Biophys Res Commun. 1996 Nov 1;228(1):100-4. doi: 10.1006/bbrc.1996.1622.
We report a highly sensitive electrochemical approach suitable for the real time measurement of insulin release from single islets of Langerhans, the functional endocrine units in the pancreas. The method is based on the detection of the insulin surrogate 5-hydroxytryptamine (5-HT) by carbon fibre microelectrodes implanted in the islets. Based on the combination of this novel approach with the simultaneous microfluorometric recording of cytosolic free Ca2+ concentration ([Ca2+]i), we demonstrate that glucose-stimulated islets secrete 5-HT/insulin in a pulsatile fashion under physiological conditions, and that this activity is encoded by synchronous [Ca2+]i oscillations. The sensitivity to detect variations in minute amounts of secreted materials is partially conferred by the fact that the tracer is released into a relatively confined space (the intraislet interstitial space).
我们报告了一种高度灵敏的电化学方法，适用于实时测量来自胰岛（胰腺中的功能性内分泌单位）单个胰岛的胰岛素释放。该方法基于通过植入胰岛中的碳纤维微电极检测胰岛素替代物5-羟色胺（5-HT）。基于这种新方法与同时进行的细胞溶质游离Ca2+浓度（[Ca2+]i）的微荧光测定记录相结合，我们证明在生理条件下，葡萄糖刺激的胰岛以脉冲方式分泌5-HT/胰岛素，并且这种活性由同步的[Ca2+]i振荡编码。检测微量分泌物质变化的灵敏度部分归因于示踪剂被释放到相对受限的空间（胰岛内间质空间）这一事实。
