, 2007 and Zlotnik et al., 2008). The neuroprotective effects of Pyr contrast with those observed following Oxa treatment since the neurological recovery of rats treated with Oxa after CHI was more complete and in markedly stronger correlation with the decrease of blood Glu levels. Thus, unlike Oxa that was suggested to exert its neuroprotective effects mainly via its blood Glu scavenging activity, Pyr is likely to use additional neuroprotective mechanisms particularly GSK2118436 when administered at high doses (Zlotnik et al., 2008). Although these conclusions were taken from a rat model of

CHI, some may be applied to our model of acute SE since both models involve Glu-mediated brain injury. Future investigations focused on long term behavioral outcome after SE may also include the monitoring for the occurrence of spontaneous

recurrent seizures which are the hallmark the chronic phase of the pilocarpine model of epilepsy Endocrinology antagonist (Arida et al., 2006 and Leite et al., 2006). As stated above, previous studies have demonstrated that systemic administration of Pyr and Oxa in rats produces blood Glu scavenging and increased brain-to-blood Glu efflux (Gottlieb et al., 2003, Zlotnik et al., 2007 and Zlotnik et al., 2008). In this context, an important issue to be addressed is the impact of Glu drop off on brain tissue, particularly neuronal cells. Preliminary results of our group indicate that naive animals (not subjected to SE) that received Pyr or Pyr + Oxa show neuronal damage in the hippocampus (unpublished data). Moreover, Gonzalez et al. (2005) showed that rapid injection

of large doses of Pyr (1–2 g/kg, i.v.) in naive rats produced a proconvulsive effect. These findings suggest that further experiments must be conducted in order to evaluate the possible deleterious effects of abnormal brain-to-blood Glu efflux on brain tissue. The acute neuronal cell loss in the hippocampus (CA1 subfield) induced by SE was completely prevented in rats treated with pyruvate plus oxaloacetate. Moreover, the late caspase-1 activation was significantly reduced when rats were treated with oxaloacetate or pyruvate plus oxaloacetate. These data support the idea that the treatment from with pyruvate and oxaloacetate causes a neuroprotective effect in rats subjected to pilocarpine-induced SE. This research was supported by CNPq, CAPES and FAPESP from Brazil. Andrezza S.R. Carvalho received a fellowship grant from CAPES. “
“In the CNS, ATP mediates a broad range of effects, varying from trophic to toxic effects, both in neurons and glial cells (for review, see Franke and Illes, 2006 and Verkhratsky et al., 2009). In the retina, it is also emerging as an important signaling molecule that can be released, through a calcium-dependent mechanism, by application of several depolarizing stimuli such as light, KCl and glutamate agonists (Newman, 2005, Perez et al., 1986 and Santos et al., 1999).