三种致惊药对小鼠不同脑区GABA_A受体抑制效应的比较研究

A Comparative Study of the Inhibition of Convulsants on GABA_A Receptor in Different Cerebral Areas of Mice

采用放射配体受体结合分析法和动物行为观察 ,研究了致惊药印防己毒素 (picrotoxin ,Pic)、青霉素 (Penicillin ,PG)、红藻氨酸 (kainicacid ,KA)对小白鼠大脑皮层、海马、小脑三脑区3 H GABA与GABAA 受体结合的影响 .结果显示 ,Pic、PG、KA均能明显降低各脑区3 H GABA与GABAA 受体的结合量 ,除PG对海马无显著差异外 ,其余均有显著性差异 (P <0 0 5或P <0 0 1 ) ,且抑制效应PG强于Pic和KA .实验结果提示 :Pic、PG、KA的致惊作用均可以通过降低GABAA 受体的结合量而实现 。

By using radioactive ligand receptor binding assay and observing animal activities, this paper reports the effects of convulsants of picrotoxin, penicillin and kainic acid on the 3H GABA A binding in the cerebral cortex, hippocampus and cerebellum of mice. The results show that they all markedly decrease the binding of 3H GABA to GABA A receptor significantly( P<0 05 or P<0 0 1) except the effect of penicillin on hippocampus( P >0 05), and that the inhibition of penicillin is the strongest. These results indicate that picrotoxin, penicillin and kainic acid can decrease the binding of 3H GABA to GABA A receptor to function as convulsants. However, they show some difference in affecting the function of GABA system in terms of ways and effects.