Nitric Oxide Synthase Inhibitors Do Not Attenuate Diacylglycerol or Monoacylglycerol Lipase Activities in Synaptoneurosomes

Neuron-enriched cultures and synaptoneurosomal fractions from 10 day-old rat brain contain diacylglycerol and monoacylglycerol lipase activities. Glutamate and its analogs stimulate the activities of diacylglycerol and monoacylglycerol lipases in a time-and dose-dependent manner. Stimulation of diacylglycerol and monoacylglycerol lipases by glutamate or NMDA can be blocked by MK-801 (non-competitive antagonist). Nitro L-arginine methyl ester and L-methylarginine have no effect on glutamate stimulated activities of diacylglycerol and monoacylglycerol lipases. Our studies suggest that synaptoneurosomal preparations from young rat brain are useful for obtaining important information on signal transduction.