Effect of cocaine, nomifensine, GBR 12909 and WIN 35428 on carbon fiber microelectrode sensitivity for voltammetric recording of dopamine
Effect of cocaine, nomifensine, GBR 12909 and WIN 35428 on carbon fiber microelectrode sensitivity for voltammetric recording of dopamine
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DOI：
10.1016/s0165-0270(00)00264-8
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发表时间：
2000-08-15
影响因子：
3
通讯作者：
Lee, TH
中科院分区：
文献类型：
--
作者：
Davidson, C;Ellinwood, EH;Lee, TH
使用伏安法或安培法在碳纤维微电极上的电化学测量已在体外和体内用于检查中枢多巴胺系统的调节机制。在许多这样的实验中，在控制条件下确定多巴胺外排浓度，然后确定它们对药物治疗的反应。目前的研究表明，一些药物不仅可以通过其预期的药理作用，还可以通过直接改变微电极的反应性来影响多巴胺的测量。常用的再摄取抑制剂GBR 12909 （10 μ M）和诺米芬（5 μ M）大大降低了电极灵敏度，并且在诺米芬的情况下，增加了对多巴胺剂量反应达到平台期的时间（即减少了“频率响应”）。可卡因（10 μ M）和WIN 35428 （2 μ M）对这些指标的影响可以忽略不计。这种敏感性的降低是发现在国家和非国家涂层电极。此外，增加反转电位（从+ 1.0到+ 1.3 V）和电压扫描速率（从350到450 V/s）并不能阻止非离子涂层电极中灵敏度的降低。这些数据表明，在使用GBR 12909或nomifenine的碳电极解释伏安或安培实验数据时必须小心，特别是在高浓度下。此外，只要可能，应确定药物对电极灵敏度和频率响应的直接影响。(C) 2000 Elsevier Science B.V.版权所有
Electrochemical measurements using voltammetry or amperometry at carbon-fiber microelectrodes have been used in vitro and in vivo to examine regulatory mechanisms for the central dopamine system. In many of these experiments, dopamine efflux concentrations under control conditions are determined followed by their alterations in response to a drug treatment. The present study demonstrates that some drugs can affect dopamine measurements, not only by their expected pharmacological action but also by directly altering the microelectrode responsivity. The commonly used reuptake inhibitors GBR 12909 (10 mu M) and nomifensine (5 mu M) drastically reduce electrode sensitivity and, in the case of nomifensine, increase the time to reach a plateau in response to dopamine boluses (i.e. reduced 'frequency response'). Cocaine (10 mu M) and WIN 35428 (2 mu M) have negligible effect on these indices. This decrease in sensitivity was found in both nafion and non-nafion coated electrodes. Further, the reduction in sensitivity seen in non-nafion coated electrodes was not prevented by increasing the reversal potential (from + 1.0 to + 1.3 V) and voltage scan rate (from 350 to 450 V/s). These data suggest that care must be taken when interpreting data from voltammetric or amperometric experiments using carbon electrodes where GBR 12909 or nomifensine are used, especially at high concentrations. Furthermore, wherever possible, direct effects of a drug on electrode sensitivity and frequency response should be determined. (C) 2000 Elsevier Science B.V. All rights reserved.