| Registro completo |
| Provedor de dados: |
BJMBR
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| País: |
Brazil
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| Título: |
Magnesium chloride alone or in combination with diazepam fails to prevent hippocampal damage following transient forebrain ischemia
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| Autores: |
Milani,H.
Lepri,E.R.
Giordani,F.
Favero-Filho,L.A.
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| Data: |
1999-10-01
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| Ano: |
1999
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| Palavras-chave: |
Cerebral ischemia
Hippocampal lesion
CA1 cell loss
Magnesium chloride
Diazepam
Neuroprotection
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| Resumo: |
In the central nervous system, magnesium ion (Mg2+) acts as an endogenous modulator of N-methyl-D-aspartate (NMDA)-coupled calcium channels, and may play a major role in the pathomechanisms of ischemic brain damage. In the present study, we investigated the effects of magnesium chloride (MgCl2, 2.5, 5.0 or 7.5 mmol/kg), either alone or in combination with diazepam (DZ), on ischemia-induced hippocampal cell death. Male Wistar rats (250-300 g) were subjected to transient forebrain ischemia for 15 min using the 4-vessel occlusion model. MgCl2 was applied systemically (sc) in single (1x, 2 h post-ischemia) or multiple doses (4x, 1, 2, 24 and 48 h post-ischemia). DZ was always given twice, at 1 and 2 h post-ischemia. Thus, ischemia-subjected rats were assigned to one of the following treatments: vehicle (0.1 ml/kg, N = 34), DZ (10 mg/kg, N = 24), MgCl2 (2.5 mmol/kg, N = 10), MgCl2 (5.0 mmol/kg, N = 17), MgCl2 (7.5 mmol/kg, N = 9) or MgCl2 (5 mmol/kg) + DZ (10 mg/kg, N = 14). Seven days after ischemia the brains were analyzed histologically. Fifteen minutes of ischemia caused massive pyramidal cell loss in the subiculum (90.3%) and CA1 (88.4%) sectors of the hippocampus (P<0.0001, vehicle vs sham). Compared to the vehicle-treated group, all pharmacological treatments failed to attenuate the ischemia-induced death of both subiculum (lesion: 86.7-93.4%) and CA1 (lesion: 85.5-91.2%) pyramidal cells (P>0.05). Both DZ alone and DZ + MgCl2 reduced rectal temperature significantly (P<0.05). No animal death was observed after drug treatment. These data indicate that exogenous magnesium, when administered systemically post-ischemia even in different multiple dose schedules, alone or with diazepam, is not useful against the histopathological effects of transient global cerebral ischemia in rats.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001000016
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| Editor: |
Associação Brasileira de Divulgação Científica
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| Relação: |
10.1590/S0100-879X1999001000016
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| Formato: |
text/html
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| Fonte: |
Brazilian Journal of Medical and Biological Research v.32 n.10 1999
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| Direitos: |
info:eu-repo/semantics/openAccess
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