Sutoo D, Akiyama K
Institute of Medical Science, University of Tsukuba, 305-8575, Tsukuba, Japan.
Neurosci Lett. 2000 Nov 10;294(1):5-8. doi: 10.1016/s0304-3940(00)01537-8.
The effect of intracerebroventricular (i.c.v.) administration of magnesium on calcium- and dopamine-dependent brain function was investigated behaviorally and biochemically. The duration of ethanol-induced sleeping time in mice was prolonged following i.c.v. administration of calcium chloride (10 micromol/kg) or dopamine (30nmol/mouse); however, it was not affected by magnesium chloride (10 or 40 micromol/kg). The ability of calcium to prolong ethanol-induced sleeping time was inhibited by the administration of magnesium chloride. The brain dopamine level in mice was significantly increased following i.c.v. administration of calcium chloride. Taking into consideration these results and those from previous studies, it is suggested that calcium enhances dopamine synthesis in the brain through a calmodulin-dependent system, and the increase in dopamine level prolongs ethanol-induced sleeping time. However, magnesium inhibits dopamine release. Therefore, magnesium may inhibit calcium-dependent brain function through dopaminergic neurons, and consequently reduce the effect of calcium on ethanol activity.
通过行为学和生物化学方法研究了脑室内注射镁对钙和多巴胺依赖的脑功能的影响。给小鼠脑室内注射氯化钙（10微摩尔/千克）或多巴胺（30纳摩尔/只）后，乙醇诱导的睡眠时间延长；然而，它不受氯化镁（10或40微摩尔/千克）影响。注射氯化镁可抑制钙延长乙醇诱导睡眠时间的能力。给小鼠脑室内注射氯化钙后，其脑多巴胺水平显著升高。考虑到这些结果以及先前研究的结果，提示钙通过钙调蛋白依赖系统增强脑内多巴胺合成，多巴胺水平升高延长乙醇诱导的睡眠时间。然而，镁抑制多巴胺释放。因此，镁可能通过多巴胺能神经元抑制钙依赖的脑功能，从而降低钙对乙醇活性的影响。
