Vidal Lucía, Alfonso Miguel, Faro Lilian F, Campos Francisco, Cervantes Rosa, Durán Rafael
Department of Functional Biology and Health Sciences, University of Vigo, Spain.
Toxicology. 2007 Jul 1;236(1-2):42-9. doi: 10.1016/j.tox.2007.03.023. Epub 2007 Mar 31.
The in vivo effects of inorganic mercury (Hg(2+)) on striatal dopamine (DA) release were studied in freely moving and conscious rats using brain microdialysis techniques. Intrastriatal administration of HgCl(2) (1mM) produced an increase in extracellular DA levels of 1717+/-375% with respect to basal levels. This effect was attenuated in a Ca(2+)-free medium (361+/-66%), after pre-treatment with reserpine (231+/-66%), and was prevented in the presence of tetrodotoxin (TTX). Thus, the HgCl(2) treatment increases striatal DA according to an external calcium and vesicular dependent mechanism, being affected by the blockade of voltage sensitive sodium channels. Moreover, HgCl(2) decreased KCl-evoked DA release. Conversely, the coinfusion of HgCl(2) with nomifensine produced increases in DA extracellular levels different to that produced by nomifensine alone, suggesting that these effects probably involve an independent DA transporter (DAT) mechanism.
采用脑微透析技术，在自由活动且清醒的大鼠体内研究了无机汞（Hg(2+)）对纹状体多巴胺（DA）释放的影响。纹状体内注射HgCl₂（1mM）后，细胞外DA水平相对于基础水平增加了1717±375%。在无钙培养基中（361±66%）、利血平预处理后（231±66%），这种效应减弱，并且在存在河豚毒素（TTX）时被阻止。因此，HgCl₂处理根据外部钙和囊泡依赖性机制增加纹状体DA，受到电压敏感性钠通道阻断的影响。此外，HgCl₂降低了氯化钾诱发的DA释放。相反，HgCl₂与诺米芬辛共同输注产生的DA细胞外水平增加不同于单独使用诺米芬辛产生的增加，这表明这些效应可能涉及独立的多巴胺转运体（DAT）机制。
