Glutamate release is involved in PAF-increased cyclic GMP levels in hippocampus.

The involvement of glutamate in PAF-increased cyclic GMP levels was studied. Glutamate treatment caused a dose-response increase of cyclic GMP levels in hippocampal slices. The presence of 1 mM glutamate did not modify the effect caused by 10(-7)M PAF. To elucidate the involvement of glutamate in this action, slices were treated with PAF in the presence of MK-801, a NMDA receptor antagonist. Results indicate that PAF-increased cyclic GMP levels were obtained by NMDA receptors activation. Finally, results obtained from the experiments performed with PAF in the presence of riluzole, to inhibit the glutamate release, demonstrated that glutamate release is a stage in the PAF-induced increase of cyclic GMP levels in hippocampus.