Enhancement of the oxygen consumption in the hippocampal slices of the guinea pig induced by glutamate and its related substances.

The effects of glutamate (Glu), kainate (Ka), and N-methyl-D-aspartate (NMDA) on the oxygen consumption of the hippocampal slices of the guinea pig were investigated. The oxygen consumption of slices at resting state was 8.43 mumol/g protein/min. Bath application of Ka (1 x 10(-8) to 1 x 10(-6) M), NMDA (1 x 10(-8) M to 1 x 10(-4) M), and Glu (1 x 10(-5) M to 5 x 10(-4) M) enhanced the oxygen consumption dose-dependently in the similar tendency although the effective doses varied for the different excitants. Subsequently the consumption was maximal at approximately 140% of the resting level. The enhancement of the oxygen consumption due to NMDA and Glu was antagonized by DL-2-amino-5-phosphonovaleric acid (APV) for NMDA and by glutamic acid diethylester (GDEE) and Joro spider toxin (JSTX) for Glu. From these results it was suggested that the increase of the oxygen consumption observed here must reflect the neuronal activation induced by these excitants.