Japanese
English
- 有料閲覧
- Abstract 文献概要
- 1ページ目 Look Inside
キンドリング形成後の発作におけるセロトニン作動系の役割については相反する結果が報告されているが,その多くは扁桃核を一次焦点とする実験についてであり,海馬発作での検討はなされていない。今回,海馬キンドリング形成後の成熟ネコを用いて,セロトニン(5-HT)前駆物質L-5-hydroxytryptophan(5-HTP)および5-HT1a受容体アゴニスト8-hydroxy-2-(di-n-propylamino)tetralin(8-OH-DPAT)の投与実験を行い,両薬物の抗けいれん効果を評価した。その結果,両薬物ともに用量依存的に海馬発作を抑制し,5-HTP40mg/kgおよび8-OH-DPAT1.Omg/kgの投与後には発作段階が有意に減少した。今回の成績から,海馬キンドリング発作におけるセロトニン作動系の重要性が示され,5-HT 1 a受容体が抑制的に関与していることが示唆された。
Serotonin (5-HT) has been considered to possess an inhibitory action against the kindling development, but the role of 5-HT in kindled seizures is unclear.
Furthermore, most previous studies have dealt with amygdaloid kindling. To clarify the role of the 5-HT system in epilepsy, we examined the effects of 5-hydroxytryptophan (5-HTP), a precursor which elevates brain 5-HT, and 8-hydroxy-2- (di-n-propylamino) tetralin (8-OH-DPAT), a 5-HT 1 a receptor agonist, on seizures kindled from the feline hippocampus (HIP). Following the completion of HIP kindling, five cats received 0.9% saline, 5-HTP (20 or 40 mg/kg, i. p.) or 8-OH-DPAT (0.1 or 1.0 mg/kg, i. v.). Drugs were administered 15 min (8-OH-DPAT) or 1 hr (5-HTP) prior to electrical stimulation at the generalized seizure triggering threshold, and the anticonvulsant effects were assessed by the behavioral seizure stage and afterdischarge (AD) duration. Both 5-HTP and 8-OH-DPAT suppressed dose-dependently HIP-kindled seizures. The administration of 5-HTP at 40 mg/kg and of 8-OH-DPAT at 1.0mg/kg produced a marked or complete suppression of HIP-kindled seizures in most of the cats tested, and was found to significantly reduce the seizure stage when compared with the saline control. Both drugs tended to shorten the AD duration, but this effect did not reach statistically significant levels. The present data suggest that the 5-HT system plays an important role in HIP-kindled seizures, and that the 5-HT 1 a receptors have an inhibitory effect on the kindled focal epileptic activity of the HIP.
Copyright © 1992, Igaku-Shoin Ltd. All rights reserved.