In vivo electrochemical recording of continuous change of magnesium in medial vestibular nucleus following vertigo induced by ice water vestibular stimulation  

作　　者：XIN Ying ZHANG ZiPin YU Ping MA FuRong MAO LanQun 

机构地区：[1]Department of Otorhinolaryngology, Peking University Third Hospital [2]Beijing National Laboratory for Molecular Sciences [3]Key Laboratory of Analytical Chemistry for Living Biosystems [4]Institute of Chemistry, Chinese Academy of Sciences

出　　处：《Science China Chemistry》2013年第2期256-261,共6页中国科学（化学英文版）

基　　金：financially supported by the National Natural Science Foundation of China (20975104, 20935005, 90813032, 21127901 for L. Mao, 91132708 for P. Yu);Beijing Municipal Natural Science Foundation (7082100 for F. Ma)

摘　　要：Vertigo is one of the most common clinical symptoms. However, the chemical processes involved in the pathological mechanism of vertigo remain to be fully understood. In this study, we investigate the dynamic changes in the magnesium (Mg 2+ ) concentration in medial vestibular nucleus (MVN) of guinea pigs following vertigo induced by vestibular ice water stimulation with an electrochemical detection method consisting of in vivo microdialysis and on-line selective electrochemical detection. Electrochemical detection of Mg 2+ was accomplished based on the current enhancement of Mg 2+ towards the electrocatalytic oxidation of NADH at the electrodes modified with the polymerized film of toluidine blue O (TBO). Selectivity for the on-line electrochemical detection against Ca 2+ was achieved by using ethyleneglcol-bis(2-aminoethylether) tetraacetic acid (EGTA) as the selective masking agent for Ca 2+ . The basal level of the extracellular Mg 2+ in the MVN of guinea pigs was determined to be 759.7 ± 176.2 M(n = 16). Upon ice water irrigation of the left external ear canal, the concentration of Mg 2+ in the MVN decreases significantly, reaches 72 ± 6% (n = 8) of the basal level, and maintains for at least 1000 s. Control experiments reveal that neither warm water irrigation of the external ear canal nor ice water irrigation of the auricle induces the decrease in the concentration of Mg 2+ in the MVN. These results demonstrate that the extracellular Mg 2+ in the MVN decreases significantly following vertigo induced by vestibular ice water stimulation. This demonstration suggests that Mg 2+ might play an important role in the pathological mechanism of vertigo.Vertigo is one of the most common clinical symptoms. However, the chemical processes involved in the pathological mechanism of vertigo remain to be fully understood. In this study, we investigate the dynamic changes in the magnesium （Mg 2＋ ） concentration in medial vestibular nucleus （MVN） of guinea pigs following vertigo induced by vestibular ice water stimulation with an electrochemical detection method consisting of in vivo microdialysis and on-line selective electrochemical detection. Electrochemical detection of Mg 2＋ was accomplished based on the current enhancement of Mg 2＋ towards the electrocatalytic oxidation of NADH at the electrodes modified with the polymerized film of toluidine blue O （TBO）. Selectivity for the on-line electrochemical detection against Ca 2＋ was achieved by using ethyleneglcol-bis（2-aminoethylether） tetraacetic acid （EGTA） as the selective masking agent for Ca 2＋ . The basal level of the extracellular Mg 2＋ in the MVN of guinea pigs was determined to be 759.7 ± 176.2 M（n = 16）. Upon ice water irrigation of the left external ear canal, the concentration of Mg 2＋ in the MVN decreases significantly, reaches 72 ± 6% （n = 8） of the basal level, and maintains for at least 1000 s. Control experiments reveal that neither warm water irrigation of the external ear canal nor ice water irrigation of the auricle induces the decrease in the concentration of Mg 2＋ in the MVN. These results demonstrate that the extracellular Mg 2＋ in the MVN decreases significantly following vertigo induced by vestibular ice water stimulation. This demonstration suggests that Mg 2＋ might play an important role in the pathological mechanism of vertigo.

关 键 词：on-line electrochemical detection in vivo microdialysis MAGNESIUM VERTIGO 

分 类 号：R764[医药卫生—耳鼻咽喉科]