Sutoo D, Akiyama K, Takita H
Institute of Medical Science, University of Tsukuba, Japan.
Brain Res. 1987 Aug 25;418(2):205-13. doi: 10.1016/0006-8993(87)90087-4.
The metabolism of various metal ions and biogenic amines in El mice, an inbred mutant strain susceptible to epilepsy, was investigated as a possible model for seizure mechanism. Serum Na, P, Ca, Mg, Fe and Zn levels in El mice were lower than those in ddY mice, the mother strain of El mice. Conversely, bone Ca, P, Na, Mg and Zn levels in El mice were higher than those in ddY mice. The results obtained by chemical analysis are consistent with radiographic observations. Possible mechanisms for the lower serum metal ion levels seen in El mice include a decrease in availability of these ions from bone. The dopamine (DA) level in El mouse brain was 15% lower than in ddY mice but could be raised by intraventricular administration of CaCl2. This result was supported a decreased ethanol-induced sleeping time in El as compared to ddY mice, with 'normalization' occurring after intraventricular administration of Da or CaCl2. The biogenic amine levels disorder in El mice is discussed on the basis of our pharmacological observation that biogenic amine synthesis is regulated by divalent cations via a calmodulin-dependent system. Our results suggest that the disorders of metal ion metabolism could be a mechanism for epileptic convulsions in El mice.
作为癫痫发作机制的一种可能模型，对近交突变株El小鼠（一种易患癫痫的品系）中各种金属离子和生物胺的代谢进行了研究。El小鼠血清中的钠、磷、钙、镁、铁和锌水平低于其母本品系ddY小鼠。相反，El小鼠骨骼中的钙、磷、钠、镁和锌水平高于ddY小鼠。化学分析结果与射线照相观察结果一致。El小鼠血清金属离子水平较低的可能机制包括这些离子从骨骼中的可利用性降低。El小鼠脑内多巴胺（DA）水平比ddY小鼠低15%，但可通过脑室内注射氯化钙来提高。与ddY小鼠相比，El小鼠乙醇诱导的睡眠时间缩短，在脑室内注射多巴胺或氯化钙后“恢复正常”，这一结果支持了上述观点。基于我们的药理学观察，即生物胺合成由二价阳离子通过钙调蛋白依赖性系统调节，对El小鼠中生物胺水平紊乱进行了讨论。我们的结果表明，金属离子代谢紊乱可能是El小鼠癫痫惊厥的一种机制。
