断乳后慢性铝暴露对大鼠海马长时程增强及蛋白激酶A表达的影响  

Effects of postweaning chronic aluminum exposure on LTP and expression of PKA in hippocampus of rats

作　　者：银杰[1] 南娟[1] 杨一鸣[2] 罗丹[1] 蔡葵[3] 时利德[1] 

机构地区：[1]中国医科大学基础医学院生理学教研室,沈阳110001 [2]中国医科大学基础医学院发育生物学教研室,沈阳110001 [3]中国医科大学基础医学院神经生物学教研室,沈阳110001

出　　处：《中华行为医学与脑科学杂志》2009年第6期529-531,共3页Chinese Journal of Behavioral Medicine and Brain Science

基　　金：国家自然科学基金资助项目（30371229）

摘　　要：目的研究断乳后不同浓度慢性铝暴露对大鼠海马长时程增强及蛋白激酶A（PKA）表达的影响，进一步探讨铝损害学习与记忆的突触机制。方法断乳的健康Wistar大鼠60只，按体质量随机平均分为3组：对照组、0．2％-A1和0．4％-A1组。各组大鼠分别自由饮用蒸馏水、Al^3＋浓度为15mmol·L^-1和30mmol·L^-1的A1C13水溶液；采用细胞外微电极记录法测定海马长时程增强，western-blot法测定大鼠海马内PKA蛋白表达。结果高频刺激（HFS）后，对照组大鼠海马长时程增强发生率为77．78％，0．2％-Al组为60％、0．4％-Al组为44．44％。对照组大鼠群体锋电位平均相对幅值达基线值（1414．69±29．91）％，0．2％-Al组为（113．57±16．47）％，0．4％-Al组为（103．91±19．96）％，0．4％-Al组与对照组相比，显著降低（P=0．033），但0．2％-Al组与对照组之间差异无显著性；对照组PKA含量为1．45±0．36；0．2％-Al组为1．024-0．22；0．4％，A1组为0．72±0．12。与对照组相比，2个铝暴露组大鼠海马内PKA蛋白表达显著减少（P=0．000），且2个铝暴露组间亦差异具有显著意义（P=0．000）。结论断乳后慢性铝暴露损害了海马长时程增强的表达，导致学习与记忆功能下降，可能与PKA表达的减少有关。Objective To study the change of LTP and the experssion of PKA in hippocampus of rats after postweaning chronic aluminum exposure of different concentration, and to go deep into the synaptic mechanism of that aluminum impairs learning and memory capacity. Methods The extraeelluar microelectrode technique was used to monitor the LTP. The expression of PKA in hippocampus was measured by the method of western-blot. Resuits The occurrence of LTP in control group was 78.78% , in 0. 2% -Al group was 60% , and in 0.4% -Al group was 44.44%. Moreover,the PS mean amplitudes relative to the baseline values after HFS in control group was （ 144.69 ± 29.91 ） %, in 0.2% -Al group was （ 113.57 ± 16.47 ） % , and in 0.4% -Al group was （ 103.91 ± 19.96） % ;compared with the control group, in 0.4%-Al group, the PS mean amplitudes relative to the baseline values were significantly decreased（P= 0.033 ）. The content of PKA in control group was 1.45 ± 0.36, in 0.2% -Al group was 1.02± 0.22 ,and in 0.4%-Al group was 0.72 ±0.12 ;compared to the control group, the expression of PKA in hippoeampus was significantly reduced in two Al3＋ exposed groups （P = 0. 000 ） , and the difference between the two exposed groups was statistically significant （P = 0.000）. Conclusion Postweaning aluminum exposure can damage the expression of LTP in hippocampus of rats, consquentely impair the ability of learning and memory, which might be related to the decrease of the expression of PKA in the hippocampus.

关 键 词：铝暴露 长时程增强 蛋白激酶A 断乳 

分 类 号：R285.5[医药卫生—中药学]