Effect of nitric oxide on L-[3H]glutamate binding to rat brain synaptic membranes.

Nitric oxide (NO), which is spontaneously generated from sodium nitroprusside, was shown to inhibit L-[3H]glutamate binding to rat brain synaptic membranes in a concentration-dependent manner. The L-glutamate binding inhibited by NO, was largely recoverable by the addition of hemoglobin, a scavenger of NO, to the assay medium. These results suggest that NO may play an important role in the modulation of excitatory neurotransmission through direct interaction of L-glutamate binding to its physiological synaptic membrane receptors.