Effects of neurotransmitter candidates on 45Ca uptake by cortical slices of rat brain: Stimulatory effect of l-glutamic acid

Abstract

The effects of neurotransmitter candidates and the characteristics of the stimulatory effect of l-glutamic acid ( l-Glu) on 45Ca uptake by rat brain slices were investigated. 45Ca uptake was significantly stimulated by acetylcholine, serotonin and especially l-Glu, but not by other neurotransmitter candidates. L-Glu caused dose-dependent stimulation of 45Ca uptake ( L-Glu-stimulated 45Ca uptake), its effect being half-maximal at 1 μM. The related compounds D-glutamic acid, D, L-α-aminoadipic acid and N-methyl- D, L-glutamic acid (final conc. of 10 μM) also stimulated 45Ca uptake, but less than 10 μM L-Glu. D, L-α-Methylglutamic acid and L-glutamic acid diethylether (final conc. of 10 μM), which are specific inhibitors of L-Glu, inhibited L-Glu-stimulated 45Ca uptake. Mg, Ca-ATPase activity was hardly affected by a concentration of 10 μM L-Glu that caused maximal stimulation of 45Ca uptake. These findings suggest that L-Glu-stimulated 45Ca uptake by brain cortical slices is linked to L-Glu receptor.