Amatore Christian, Arbault Stéphane, Bouret Yann, Cauli Bruno, Guille Manon, Rancillac Armelle, Rossier Jean
Ecole Normale Supérieure, Département de Chimie, UMR CNRS-ENS-UPMC 8640 Pasteur, 24 rue Lhomond, 75231 Paris Cedex 05, France.
Chemphyschem. 2006 Jan 16;7(1):181-7. doi: 10.1002/cphc.200500202.
Nitric oxide is an important biological messenger that particularly induces the relaxation of smooth muscle cells surrounding vessels, and, hence, controls the flow of blood. This mechanism is essential for brain function, and its fine control, termed functional hyperemia, is supposed to be realized by certain neurons that may release bursts of NO*. The aim of the present study is to examine the advantages of platinized carbon-fiber microelectrodes (5-7 microm tip diameter) for the direct and in situ electrochemical detection of NO* released by neurons into ex vivo cerebellum slices. After establishing the different analytical properties of the platinized carbon-fiber microelectrodes in vitro on NO* solutions at 50 nM to 1 mM concentration, they were characterized using DEA-NONOate solutions that chemically decompose into NO*, and therefore mimic the measurement of transient variations of NO* concentration in biological samples. This validated the present approach, so that direct, in situ ex vivo measurements of nitric oxide released by neurons in a rat cerebellar slice are presented and discussed.
一氧化氮是一种重要的生物信使，它尤其能诱导血管周围平滑肌细胞的舒张，从而控制血液流动。这一机制对大脑功能至关重要，其精细调控，即功能性充血，据推测是由某些可能释放一氧化氮爆发的神经元来实现的。本研究的目的是检验镀铂碳纤维微电极（尖端直径5 - 7微米）用于直接原位电化学检测神经元释放到离体小脑切片中的一氧化氮的优势。在体外确定了镀铂碳纤维微电极在浓度为50 nM至1 mM的一氧化氮溶液中的不同分析特性后，使用能化学分解为一氧化氮的DEA - NONOate溶液对其进行表征，从而模拟生物样品中一氧化氮浓度瞬变的测量。这验证了当前方法，因此展示并讨论了对大鼠小脑切片中神经元释放的一氧化氮进行直接原位离体测量的结果。
