Tsuji A, Sato H, Kume Y, Tamai I, Okezaki E, Nagata O, Kato H
Faculty of Pharmaceutical Sciences, Kanazawa University, Japan.
Antimicrob Agents Chemother. 1988 Feb;32(2):190-4. doi: 10.1128/AAC.32.2.190.
The specific binding of 3H-labeled gamma-aminobutyric acid ([3H]GABA) to synaptic plasma membranes from rat brains was inhibited by various quinolonecarboxylic acid derivatives (quinolones), and these inhibitions were concentration dependent. The binding of [3H]muscimol to GABAA sites was also inhibited. These inhibitory potencies differed widely among the quinolones examined. The Dixon plots showed that a newly developed difluorinated quinolone, NY-198 [1-ethyl-6,8-difluoro-1,4-dihydro-7-(3-methyl-1-piperazinyl)-4-oxo-3- quinolinecarboxylic acid hydrochloride], competitively inhibits the receptor bindings of [3H]GABA and [3H]muscimol. In conclusion, our findings suggest that the inhibition of GABA binding to receptors (including uptake sites) in the brain may be involved in the induction of epileptogenic neurotoxicities by quinolones.
3H标记的γ-氨基丁酸([3H]GABA)与大鼠脑突触质膜的特异性结合受到多种喹诺酮羧酸衍生物(喹诺酮类)的抑制,且这些抑制作用呈浓度依赖性。[3H]蝇蕈醇与GABAA位点的结合也受到抑制。在所检测的喹诺酮类药物中,这些抑制效力差异很大。Dixon图表明,一种新开发的二氟喹诺酮NY-198 [1-乙基-6,8-二氟-1,4-二氢-7-(3-甲基-1-哌嗪基)-4-氧代-3-喹啉羧酸盐酸盐]竞争性抑制[3H]GABA和[3H]蝇蕈醇的受体结合。总之,我们的研究结果表明,喹诺酮类药物抑制大脑中GABA与受体(包括摄取位点)的结合可能与诱发性癫痫神经毒性有关。