甲基汞对大鼠脑突触体谷氨酸摄取的抑制作用

Inhibition of glutamate uptake in rat brain synaptosome by methylmercury

应用高亲和性摄取试验研究了甲基汞在体外对大鼠脑突触体谷氨酸摄取的影响。结果表明，１×１０－９～１×１０－４ｍｏｌ／Ｌ甲基汞可使大鼠大脑皮层、海马、纹状体和小脑突触体３Ｈ－Ｌ－谷氨酸摄取量分别下降０．７％～７４．４％、７．５％～９１．１％、１．４％～７６．６％和４．４％～７７．０％，其中在１×１０－６～１×１０－４ｍｏｌ／Ｌ范围内均有显著性意义（Ｐ＜０．０５），且均存在明显的剂量—效应关系，其抑制作用的ＩＣ５０分别为７．９、３．６、２．２和４．３×１０－６ｍｏｌ／Ｌ。本研究结果提示甲基汞可明显抑制大鼠脑突触体高亲和谷氨酸摄取功能。

The effect of methylmercury on the glutamate uptake in rat brain synaptosomes were studied in vitro by using a high affinity uptake test.The result showed that methylmercury(1×10 -9 ～1×10 -4 mol/L)could decrease 3H L glutamate uptake in rat cerebral cortex,hippocampus, striatum and cerebellum synaptosome by 0.7%～74.4%,7.5%～91.1%,1.4%～76.6% and 4.4%～77.0%,respectively,in a dose dependent manner,and their IC 50 were 7.9, 3.6, 2.2 and 4.3×10 -6 mol/L,respectively.It suggested that methylmercury could obviously inhibit glutamate uptake in the synaptosomes of rat brain.