Further evidence for a role of nitric oxide in experimental allergic encephalomyelitis: aminoguanidine treatment modifies its clinical evolution

The role of nitric oxide (NO) in inflammatory/demyelinating diseases is und ergoing extensive investigation as a potential target for therapeutic inter vention. However, interference with NO production has resulted in contrasti ng effects on the development of experimental allergic encephalomyelitis (E AE), the most widely used experimental model for multiple sclerosis (MS). P urpose of this paper was both the analysis of the individual clinical evolu tion of EAE induced in Lewis female rats by active immunisation and the eva luation of the effect of treatment with aminoguanidine, a selective inhibit or for the inducible isoform of nitric oxide synthase (iNOS). In our experi mental model, relapse occurred in 66% of animals. Aminoguanidine treatment, started 3 days before immunisation, guaranteed a complete recovery from th e acute phase and a delayed, milder relapse. Moreover, 79 days after immuni sation inflammatory cellular infiltrates in the spinal cord were reduced. T hese data further support the involvement of NO in EAE evolution. (C) 2000 Elsevier Science B.V. All rights reserved.