Comparison of amperometric methods for detection of exocytosis from single pancreatic β-cells of different species
Comparison of amperometric methods for detection of exocytosis from single pancreatic β-cells of different species
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DOI：
10.1021/ac990817e
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发表时间：
1999-12-15
影响因子：
7.4
通讯作者：
Kennedy, RT
中科院分区：
文献类型：
--
作者：
Aspinwall, CA;Huang, L;Kennedy, RT
比较了两种安培检测单个胰腺β细胞胞吐的方法。在第一，直接检测胰岛素是使用胰岛素敏感的化学修饰电极。在第二种方法中，用裸碳电极检测已经被允许在β细胞分泌囊泡内积累的5-羟色胺（5-HT）。比较的目的是确定5-HT分泌是否是单个β细胞中胰岛素分泌的有效标志物。为了帮助进行这种比较，一些实验涉及在先前允许积累5-HT的细胞中同时测量胰岛素和5-HT。在应用常见的胰岛素促分泌素时，获得由5-HT、胰岛素或这两种化合物的检测引起的电流尖峰，指示通过胞吐作用的分泌。从同时测量获得的电流尖峰的平均面积等于独立测量的胰岛素和5-HT的平均面积的总和。此外，对于几种常见的促分泌素，对检测胰岛素、5-HT或这两种化合物获得的尖峰数量的分析是相似的。这些数据支持的假设，积累的5-HT是从含有胰岛素的分泌囊泡释放，排他。此外，还比较了不同种属β细胞的胰岛素和5-HT测量值，以确定此处比较的两种方法是否存在种属依赖性。在人、猪和犬β细胞中，5-HT的检测导致与胰岛素在频率和振幅上相当的类似数量的尖峰;然而，在小鼠和INS-1 β细胞中，5-HT比胰岛素更容易检测到。
Two methods for amperometric detection of exocytosis at single pancreatic beta-cells were compared. In the first, direct detection of insulin was accomplished using an insulin-sensitive chemically modified electrode. In the second, 5-hydroxytryptamine (5-HT) that had been allowed to accumulate within the beta-cell secretory vesicles was detected with a bare carbon electrode, The goal of the comparison was to determine whether 5-HT secretion was a valid marker of insulin secretion in single beta-cells. To aid in this comparison, some experiments involved simultaneous measurement of insulin and 5-HT at cells previously allowed to accumulate 5-HT. Upon application of common insulin secretagogues, current spikes resulting from detection of 5-HT, insulin, or both compounds were obtained indicative of secretion via exocytosis. The mean area of current spikes obtained from simultaneous measurements equaled the sum of the mean area of insulin and 5-HT measured independently. Additionally, analyses of the number of spikes obtained for detection of insulin, 5-HT, or both compounds were similar for several common secretagogues. These data support the hypothesis that accumulated 5-HT is released from insulin containing secretory vesicles, exclusively. In addition, measurement of insulin and 5-HT from beta-cells of different species was compared to determine whether a species dependence exists for the two methods compared here. Detection of 5-HT results in a similar number of spikes that are equivalent to insulin in frequency and amplitude in human, porcine, and canine beta-cells; however, in mouse and INS-1 beta-cells, 5-HT is more readily detected than insulin.