铝染毒对大鼠大脑皮层Ryr_2和L-Ca^(2+) α1c基因表达的影响

Effects of aluminum on the expression of Ryr_2 and L-Ca^(2+) α1c genes in the cortex of wistar rats

目的研究铝对大鼠大脑皮层细胞中Ryanodine受体2(ryanodine receptor,Ryr2)和L-型钙通道α1C亚基(α1Csubunit of L-type calcium channels,L-Ca2+α1C)基因表达的影响,探讨铝对细胞内钙浓度改变的机制。方法健康Wistar大鼠随机分为4组,分别按照大鼠氯化铝经口LD50的1/15 LD50(248.7 mg/kg)、1/50 LD50(74.7 mg/kg)、1/100 LD50(37.3mg/kg)给予灌胃染毒,同时设立阴性对照组(蒸馏水)。连续灌胃120 d,分别在染毒45、75和120 d和染毒结束后30 d处死4只实验动物,取大脑皮层。应用荧光定量链式反应(RT-PCR)方法,检测各组动物皮层中Ryr2和L-Ca2+α1c基因表达情况。结果染毒大鼠大脑皮层中Ryr2mRNA表达显著高于对照组;各组动物大脑皮层中Ryr2mRNA表达均随时间延长而增高;染毒大鼠大脑皮层细胞中L-Ca2+α1c mRNA表达在不同染毒时期均高于对照组;各组动物大脑皮层中L-Ca2+α1c mRNA表达均随时间延长而降低。结论铝可引起大脑皮层中Ryr2和L-Ca2+α1c基因表达的增加,而增加细胞内游离钙浓度,从而发挥神经毒性作用。

Objective To explore the mechanism of aluminum raising the concentration of intraeellular Ca^2＋ on the neuronal cell on the cortex. Methods 64 Wistar rats were divided into 4 groups randomly, and were lavaged at 248.7, 74.7, 37.3 and 0 mg/kg aluminum chloride （A1CI3） respectively. The rats were sacrificed at the 45, 75 and 120 d after lavaged, and 30 d after stopping lavage. RT-PCR method was used to observe the expression of Ryr2 and L-Ca^2＋ cde Genes in the Cortex neuronal. Results Aluminum could increase the expressions of Ryr2 and L-Ca^2＋ ale Genes in the Cortex, and Ryr2 gene showed higher expression with the time, however L- Ca^2＋ ale displayed a different expression. Conclusion Aluminium can increase the expression of Ryh , induce the L-Ca^2＋ ale channel open, increase the Ca^2＋ flowing into the cell. But if the Al^3＋ is accumulated to some degree, it can inhibit the open of the L-Ca^2＋ ode channel.