Magnesium chloride alone or in combination with diazepam fails to prevent hippocampal damage following transient forebrain ischemia
Braz. j. med. biol. res
; 32(10): 1285-93, Oct. 1999. graf
Artigo
em Inglês
| LILACS
| ID: lil-252280
Biblioteca responsável:
BR1.1
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 percent) and CA1 (88.4 percent) sectors of the hippocampus, 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 percent) and CA1 (lesion 85.5-91.2 percent) pyramidal cells. Both DZ alone and DZ + MgCl2 reduced rectal temperature significantly. No animaldeath 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
Texto completo:
Disponível
Coleções:
Bases de dados internacionais
Contexto em Saúde:
ODS3 - Meta 3.4 Reduzir as mortes prematuras devido doenças não transmissíveis
Problema de saúde:
Doença Cardiovascular
/
Doença Cerebrovascular
Base de dados:
LILACS
Assunto principal:
Cloreto de Magnésio
/
Ataque Isquêmico Transitório
/
Prosencéfalo
/
Fármacos Neuroprotetores
/
Diazepam
/
Hipocampo
Limite:
Animais
Idioma:
Inglês
Revista:
Braz. j. med. biol. res
Assunto da revista:
Biologia
/
Medicina
Ano de publicação:
1999
Tipo de documento:
Artigo