低镁引起的幼年大鼠内嗅皮层脑片场电位的变化及Kava内酯的作用

LOW MAGNESIUM INDUCED CHANGES OF FIELD POTENTIALS AND ROLE OF LACTONE KAVA IN THE ENTORHINAL CORTEX SLICES OF INFANT RAT

降低细胞外镁离子浓度可引起幼年大鼠（２～３周）的内嗅皮层脑片的癫痫样放电。这种放电分为早期间歇性和晚期连续性两种模式。ＮＭＤＡ受体通道阻断剂ＭＫ－８０１完全抑制这种癫痫样放电。五种新合成的Ｋａｖａ内酯的同分异构化合物对这种放电有不同程度的抑制作用，其药物作用的强度依次为：Ｋａｖａｉｎ＝Ｍｅｔｈｙｓｔｉｃｉｎ＞ＤＨ－Ｋａｖａｉｎ＞ＤＨ－Ｍｅｔｈｙｓｔｉｃｉｎ＞Ｋａｖａ－Ｋａｖａｉｎ。

Lowering of extracellular Mg 2+ concentration induced epileptiform discharges in the entorhinal cortex slices of infant rats (two～three weeks). The discharges were grouped under two patterns: the early seizure like events and the late tonic recurrents. The NMDA receptor antagonist MK 801 inhibited this kind of epileptiform discharges compeletely. Five new synthesized isomers of Lactone KAVA inhibited this discharges in different degrees, their strength sequence of inhibitory effectiveness was: Kavain>Methysticin>DH Kavain>DH Methysticin>Kava Kavain.