Acute and repeated restraint stress influences cellular damage in rat hippocampal slices exposed to oxygen and glucose deprivation.
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.
Fontella
Fernanda Urruth
FU
PPG-Fisiologia e Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, Rua Ramiro Barcelos, 2600 anexo, 90035-003 Porto Alegre, RS, Brazil.
Cimarosti
Helena
H
Crema
Leonardo Machado
LM
Thomazi
Ana Paula
AP
Leite
Marina Concli
MC
Salbego
Christianne
C
Gonçalves
Carlos Alberto Saraiva
CA
Wofchuk
Susana
S
Dalmaz
Carla
C
Netto
Carlos Alexandre
CA
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
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