title: Effects of 3 weeks GMP oral administration on glutamatergic parameters in mice neocortex.
abstract: Overstimulation of the glutamatergic system (excitotoxicity) is involved in various acute and chronic brain diseases. Several studies support the hypothesis that guanosine-5'-monophosphate (GMP) can modulate glutamatergic neurotransmission. The aim of this study was to evaluate the effects of chronically administered GMP on brain cortical glutamatergic parameters in mice. Additionally, we investigated the neuroprotective potential of the GMP treatment submitting cortical brain slices to oxygen and glucose deprivation (OGD). Moreover, measurements of the cerebrospinal fluid (CSF) purine levels were performed after the treatment. Mice received an oral administration of saline or GMP during 3 weeks. GMP significantly decreases the cortical brain glutamate binding and uptake. Accordingly, GMP reduced the immunocontent of the glutamate receptors subunits, NR2A/B and GluR1 (NMDA and AMPA receptors, respectively) and glutamate transporters EAAC1 and GLT1. GMP treatment significantly reduced the immunocontent of PSD-95 while did not affect the content of Snap 25, GLAST and GFAP. Moreover, GMP treatment increased the resistance of neocortex to OGD insult. The chronic GMP administration increased the CSF levels of GMP and its metabolites. Altogether, these findings suggest a potential modulatory role of GMP on neocortex glutamatergic system by promoting functional and plastic changes associated to more resistance of mice neocortex against an in vitro excitotoxicity event.
authors: Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-anexo, 90035-003, Porto Alegre, RS, Brazil, ganzellam@hotmail.com.
authors: Marcelo
authors: M
authors: Ganzella
authors: Julia Dubois
authors: JD
authors: Moreira
authors: Roberto Farina
authors: RF
authors: Almeida
authors: Ana Elisa
authors: AE
authors: Böhmer
authors: Jonas Alex Morales
authors: JA
authors: Saute
authors: Silvia
authors: S
authors: Holmseth
authors: Diogo Onofre
authors: DO
authors: Souza