三种致惊药对小鼠不同脑区GABAA受体抑制效应的比较研究

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(kainic acid,KA)对小白鼠大脑皮层、海马、小脑三脑区3H-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3H-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＜0.05或P＜0.01),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,但它们影响GABA能系统活动的途径及效应存在差异.

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

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.