title: Acute and repeated restraint stress influences cellular damage in rat hippocampal slices exposed to oxygen and glucose deprivation.
abstract: Several studies have shown that high corticosteroid hormone levels increase neuronal vulnerability. Here we evaluate the consequences of in vivo acute or repeated restraint stress on cellular viability in rat hippocampal slices suffering an in vitro model of ischemia. Cellular injury was quantified by measuring lactate dehydrogenase (LDH) and neuron-specific enolase released into the medium. Acute stress did not affect cellular death when oxygen and glucose deprivation (OGD) was applied both immediately or 24h after restraint. The exposure to OGD, followed by reoxygenation, resulted in increased LDH in the medium. Repeated stress potentiated the effect of OGD both, on LDH and neuron-specific enolase released to the medium. There was no effect of repeated stress on the release of S100B, an astrocytic protein. Additionally, no effect of repeated stress was observed on glutamate uptake by the tissue. These results suggest that repeated stress increases the vulnerability of hippocampal cells to an in vitro model of ischemia, potentiating cellular damage, and that the cells damaged by the exposure to repeated stress+OGD are mostly neurons. The uptake of glutamate was not observed to participate in the mechanisms responsible for rendering the neurons more susceptible to ischemic damage after repeated stress.
authors.affiliation: PPG-Fisiologia e Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, Rua Ramiro Barcelos, 2600 anexo, 90035-003 Porto Alegre, RS, Brazil.
authors.forename: Fernanda Urruth
authors.initials: FU
authors.lastname: Fontella
authors.forename: Helena
authors.initials: H
authors.lastname: Cimarosti
authors.forename: Leonardo Machado
authors.initials: LM
authors.lastname: Crema
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Thomazi
authors.forename: Marina Concli
authors.initials: MC
authors.lastname: Leite
authors.forename: Christianne
authors.initials: C
authors.lastname: Salbego
authors.forename: Carlos Alberto Saraiva
authors.initials: CA
authors.lastname: Gonçalves
authors.forename: Susana
authors.initials: S
authors.lastname: Wofchuk
authors.forename: Carla
authors.initials: C
authors.lastname: Dalmaz
authors.forename: Carlos Alexandre
authors.initials: CA
authors.lastname: Netto
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005947:Glucose / Q000172:deficiency*; D018698:Glutamic Acid / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology; D000860:Hypoxia; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D009414:Nerve Growth Factors / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012149:Restraint, Physical / Q000379:methods; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000378:metabolism; D012964:Sodium / Q000494:pharmacology; D013312:Stress, Physiological / Q000378:metabolism*; D013997:Time Factors
chemical_list: D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579158:S100b protein, rat; D018698:Glutamic Acid; D012964:Sodium; D007770:L-Lactate Dehydrogenase; D010751:Phosphopyruvate Hydratase; D005947:Glucose