Fructose-1,6-bisphosphate inhibits the expression of inducible nitric oxide synthase caused by oxygen-glucose deprivation through the inhibition of glutamate release in rat forebrain slices

Fructose-1,6-bisphosphate (FBP) is a glycolytic pathway intermediate with a neuroprotective action in animal models of brain ischaemia. We addressed the question of whether FBP acts through inhibiting inducible nitric oxide synthase (iNOS) expression via reduction of glutamate release, since we have recently demonstrated that glutamate is involved in the expression of iNOS. FBP (5 mM) added to the incubation solution of rat forebrain slices subjected to oxygen-glucose deprivation (OGD) inhibited glutamate release significantly (around 40%). FBP also inhibited the induction of the calcium-independent NOS activity and reduced the levels of iNOS protein in rat forebrain slices subjected to OGD. We conclude that the action of FBP by reducing glutamate release and iNOS expression, both of which have been implicated in cell damage, is a reason for further evaluation of FBP as a neuroprotectant.