Oxygen microsensor and its application to single cells and mouse pancreatic islets
Oxygen microsensor and its application to single cells and mouse pancreatic islets
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DOI：
10.1021/ac990271w
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发表时间：
1999-09-01
影响因子：
7.4
通讯作者：
Kennedy, RT
中科院分区：
文献类型：
--
作者：
Jung, SK;Gorski, W;Kennedy, RT
研制了一种尖端直径小于3 μ m的氧微传感器，用于监测单细胞和小鼠胰岛的氧水平。该传感器是通过电化学凹陷内拉玻璃微量吸管蚀刻铂线，然后用醋酸纤维素涂层。发现该制造过程比以前的具有可比尺寸的氧电极设计更简单。微传感器的平均灵敏度为0.59 +/- 0.29 pA/mmHg（平均值+/- SD，n = 42），信号受对流干扰最小，响应时间< 1 s。电极用于测量单个小鼠胰岛周围和内部的氧梯度。测量结果表明，在最大葡萄糖刺激下，即使是最大胰岛内的氧水平也为67 +/- 1.6 mmHg（平均值+/- SD，n = 5），表明胰岛在组织培养条件下通过扩散具有足够的氧供应，以支持胰岛素分泌。该电极还用于记录作为葡萄糖浓度的函数的单个胰岛处的氧水平的动态。当葡萄糖水平从3 mM变为10 mM时，氧水平降低15.8 +/- 2.3 mmHg（平均值+/- SEM，n = 6），氧水平出现周期为3.3 +/- 0.6 min（平均值+/- SEM，n = 6）的振荡。在胰岛中浸泡在静态溶液中含有10 mM葡萄糖，可以观察到类似的振荡。此外，在安静溶液中，可以检测到叠加在较慢振荡上的周期为12.1 +/- 1.7 s（平均值+/- SEM，n = 6）的较快振荡。使用该电极还可以在单个胰岛素瘤细胞上观察到氧消耗。单个细胞也表现出氧消耗的振荡，周期为几秒钟。结果表明，该电极可用于生物微环境中的动态氧水平记录。
xrAn oxygen microsensor with a < 3-mu m tip diameter was developed for monitoring oxygen levels at single cells and mouse pancreatic islets. The sensor was fabricated by electrochemically recessing an etched Pt wire inside a pulled glass micropipet and then coating with cellulose acetate. This fabrication process was found to be simpler than previous oxygen electrode designs of comparable size. The microsensors had a average sensitivity of 0.59 +/- 0.29 pA/mmHg (mean +/- SD, n = 42), signals that were minimally perturbed by convection, and response times of < 1 s, The electrode was used to measure the oxygen gradient around and inside single mouse islets. The measurements demonstrate that oxygen levels within even the largest islets at maximal glucose stimulation are 67 +/- 1.6 mmHg (mean +/- SD, n = 5), indicating that islets have adequate oxygen supplies by diffusion under tissue culture conditions to support insulin secretion. The electrode was also used to record the dynamics of oxygen level at single islets as a function of glucose concentration. As glucose level was changed from 3 to 10 mM, oxygen level decreased by 15.8 +/- 2.3 mmHg (mean +/- SEM, n = 6) and oscillations with a period of 3.3 +/- 0.6 min (mean +/- SEM, n = 6) appeared in the oxygen level. In islets bathed in quiescent solutions containing 10 mM glucose, similar oscillations could be observed. In addition, in the quiet solutions it was possible to detect faster oscillations with a period of 12.1 +/- 1.7 s (mean +/- SEM, n = 6) superimposed on the slower oscillations. Oxygen consumption could also be observed at single insulinoma cells using the electrode. Individual cells also showed oscillations in oxygen consumption with a period of a few seconds. The results demonstrate that the electrode can be used for dynamic oxygen level recordings in biological microenvironments.