铝暴露对哺乳期大鼠海马中钙调素依赖性蛋白激酶Ⅱ含量及活力的影响

Effects of Aluminium Exposure on α-CaMKⅡ in Hippocampus of Lactational Rats

目的研究慢性铝暴露对哺乳期大鼠海马中钙调素依赖性蛋白激酶Ⅱ(CaMKⅡ)含量及活力的影响,探讨铝暴露损害学习、记忆的作用机制。方法将清洁级孕期Wistar大鼠随机分为对照组、低剂量和高剂量组,每组6只。仔鼠出生后第1天,分别用含有0,0.2%和0.4%AlCl3的蒸馏水喂养母鼠。仔鼠出生后第21天(哺乳期结束),测定其全血和脑组织中的铝含量、海马中CaMKⅡ含量及活力。结果高、低剂量组仔鼠血铝和脑铝含量均高于对照组,经q检验,差异有统计学意义(P<0.05);且血铝及脑铝含量均随着铝暴露浓度的升高而升高。高、低剂量组仔鼠海马中α-CaMKⅡ的含量及活力均低于对照组,经q检验,差异有统计学意义(P<0.05);且α-CaMKⅡ的含量及活力均随着铝暴露浓度的升高而降低。结论铝暴露使仔鼠海马中α-CaMKⅡ的蛋白表达和活力降低,可能是造成学习、记忆功能损害的原因之一。

Objective To explore the mechanism of aluminum-induced damage of learning and memory by studying the change of calcium-calmodulin-dependent protein kinase Ⅱ(CaMKⅡ) in the hippocampus of lactational rats. Methods Three groups of clean pregnant Wistar rats (120-200 g) were randomly divided into 3 groups. On the first day of parturition, the dams of two groups were given 0.3% and 0.6% AlCl3 through drinking water and terminated on the weaning day (21 days). Western blot was used to determine the content and activity of α-CaMKⅡ. Results The aluminum levels in the blood and brain of aluminum-treated rats were obviously higher than that in the control (P<0.05) in a dose-dependent manner. The content and activity of α-CaMKⅡ in the hippocampus of aluminum exposed group decreased in a dose-dependent manner compared with the control group (P<0.05). Conclusion Chronic aluminum exposure can decrease the activity and content of CaMKⅡ, which will play a most important role in the damage of learning and memory induced by aluminum.