Data/hora: 01/06/2024 16:22:34

Provedor de dados: 	56	
País: 	Brazil	
Título: 	Magnesium chloride alone or in combination with diazepam fails to prevent hippocampal damage following transient forebrain ischemia	
Autores: 	Milani,H.; Lepri,E.R.; Giordani,F.; Favero-Filho,L.A.	
Data: 	1999-10-01	
Ano: 	1999	
Palavras-chave: 	Cerebral ischemia; Hippocampal lesion; CA1 cell loss; Magnesium chloride; Diazepam; Neuroprotection.	
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&amp;lt;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&amp;gt;0.05). Both DZ alone and DZ + MgCl2 reduced rectal temperature significantly (P&amp;lt;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.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001000016	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/S0100-879X1999001000016	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.32 n.10 1999	
Fonte: 	info:eu-repo/semantics/openAccess