カイニン酸, キスカル酸およびその拮抗薬投与にともなう脳波および線条体モノアミン代謝産物の変動

The CNS action of kanie acid (KA), quisqualic acid (QA) and 1-(4-chlorobenzoyl)-piperazine-2, 3-dicarboxylic acid (pCB-PzDA) was investigated in male Sprague Dawley rats, and their effects on monoamina metabolite levels in rat striatum were studied using brain dialysis. Intracerebroventricularly injected KA and QA (100nmol) induced spike discharges, and pCB-PzDA (100nmol) suppressed electrocorticograms (ECoG) for 1 hour. pCB-PzDA aggravated KA induced spike discharges and inhibited QA-induced spike discharges. Dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) levels increased transitorily by injection of 100nmol and continuously by injection of 100nmol of KA. KA increased the 5-hydroxyindoleachtic acid (5-HIAA) level 2 hours after the administration dose-dependently. Though 10nmol of QA increased the HVA level slightly, 100nmol of QA increased the DOPAC, HVA and 5-HIAA levels. Though 100nmol of pCB-PzDA increased the DOPAC and HVA levels, it inhibited the increases in DOPAC, HVA and 5-HIAA levels induced by KA. On the other hand,pCB-PzDA inhibited the increases in DOPAC, HVA and 5-HIAA levels induced by QA for 1 hour, after which the DOPAC and HVA levels increased additively. These finding suggest that pCB-PzDA acts not only as a non-NMDA antagonist but also on dopaminergic neurons directly.