微电泳给予回苏灵对家兔小脑皮层单位放电的影响

文献报道呼吸复苏剂回苏灵(dimefline,DIM)的作用可能是阻断 GABA 受体。本工作选择 GABA 受体密集的小脑皮层用微电泳方法对此加以验证。用五管玻璃微电极记录了16只家兔小脑皮层100个自发放电单位。除8个单位对 GABA、DIM 均不敏感外,有92个单位对 GABA 敏感。微电泳给予 DIM 能使这些单位的放电出现兴奋,阻遏及先兴奋后阻遏等不同效应。在75个 GABA 敏感的单位中,有71个单位 DIM 能对抗 GABA 的阻遏效应或使该单位对 GABA 的敏感性下降,未能对抗 GABA 作用的单位只有4个。静脉注射 DIM 能产生相似的结果。在35个 GABA 敏感的单位中,比较了荷包牡丹碱(bicuculline,BIC)与DIM 对 GABA 阻遏效应的影响。其中两者均能对抗 GABA 效应的有21个,两者都不能对抗的有3个,还有11个单位则 BIC 不能对抗而 DIM 能对抗。本工作提示,DIN 能对抗GABA 的阻遏效应,可作为 GABA 受体的阻断剂。

EFFECTS OF MICROIONTOPHORETICALLY APPLIED DIMEFLINE ON UNITS WITH SPONTANEOUS DISCHARGE IN THE CEREBELLAR CORTEX OF RABBIT

Experiments were carried out on 16 paralyzed and artificially ventilated rab-bits.The effects of dimefline given iontophoretically on the unit discharge ratewere examined.Of the 100 units recorded,92 were depressed by GABA,8 wereinfluenced by neither GABA nor dimefline.Dimefline given iontophoreticallypresented various types of responses,such as excitation,depression and diphasic-changes,etc.It also blocked the GABA-induced depression or decreased the sen-sitivity of GABA receptors in 71 out of 75 trials.The similar results were seenwith dimefline given intravenously.The effects of dimefline and bicuculline admini-stered iontophoretically on the GABA-sensitive units were compared.Both di-mefline and bicuculline blocked the GABA-induced depression in 21 out of 35trials,3 were not blocked,bicuculline did not block this depression but dimeflinedid in 11.The results indicate that dimefline can antagonize GABA-induced depressionand may act as a GABA receptor antagonist.