BACKGROUND: This study was to delineate the therapeutic efficacy and potential cellular and molecular mechanisms of aminoguanidine (AG), a relatively selective inhibitor of iNOS activity, in cerebral vasospasm after subarachnoid hemorrhage (SAH) in rabbits. METHODS: SAH was induced by a single injection of autologous arterial blood into the cisterna magna of adult male rabbits. An intravenous bolus injection of AG (150 mg/kg) was administrated 1h after SAH, and this dosage was repeated on the following day. Vasospasm was verified by computed tomography angiography (CTA) day 2 after SAH. Rabbit basilar arteries were harvested for transmission electron microscopy (TEM), immunohistochemical examination, RT-PCR, and western blot analysis. RESULTS: CTA data revealed that cerebral vasospasm of SAH rabbits was significantly prevented via AG treatment. TEM results demonstrated the ultrastructural morphological changes of endothelial cells of SAH rabbits were ameliorated by AG treatment. In parallel, AG treatment increased eNOS mRNA and protein levels along with the reduced immunoreactivity of nitrotyrosine in rabbit basilar arteries. CONCLUSIONS: Our discovery suggested AG inhibition of iNOS activity could significantly reverse cerebral vasospasm after SAH via restoration of dysfunctional endothelial cells by the upregulation of eNOS, indicating a regulatory cross-talk between eNOS and iNOS in the pathogenesis of SAH. Copyright (c) 2010 Elsevier B.V. All rights reserved.
BACKGROUND: This study was to delineate the therapeutic efficacy and potential cellular and molecular mechanisms of aminoguanidine (AG), a relatively selective inhibitor of iNOS activity, in cerebral vasospasm after subarachnoid hemorrhage (SAH) in rabbits. METHODS:SAH was induced by a single injection of autologous arterial blood into the cisterna magna of adult male rabbits. An intravenous bolus injection of AG (150 mg/kg) was administrated 1h after SAH, and this dosage was repeated on the following day. Vasospasm was verified by computed tomography angiography (CTA) day 2 after SAH. Rabbit basilar arteries were harvested for transmission electron microscopy (TEM), immunohistochemical examination, RT-PCR, and western blot analysis. RESULTS: CTA data revealed that cerebral vasospasm of SAH rabbits was significantly prevented via AG treatment. TEM results demonstrated the ultrastructural morphological changes of endothelial cells of SAHrabbits were ameliorated by AG treatment. In parallel, AG treatment increased eNOS mRNA and protein levels along with the reduced immunoreactivity of nitrotyrosine in rabbit basilar arteries. CONCLUSIONS: Our discovery suggested AG inhibition of iNOS activity could significantly reverse cerebral vasospasm after SAH via restoration of dysfunctional endothelial cells by the upregulation of eNOS, indicating a regulatory cross-talk between eNOS and iNOS in the pathogenesis of SAH. Copyright (c) 2010 Elsevier B.V. All rights reserved.
Authors: Serge Marbacher; Edin Nevzati; Davide Croci; Salome Erhardt; Carl Muroi; Stephan M Jakob; Javier Fandino Journal: Transl Stroke Res Date: 2014-10-19 Impact factor: 6.829
Authors: Virginia M Miller; Jay R Kaplan; Nicholas J Schork; Pamela Ouyang; Sarah L Berga; Nanette K Wenger; Leslee J Shaw; R Clinton Webb; Monica Mallampalli; Meir Steiner; Doris A Taylor; C Noel Bairey Merz; Jane F Reckelhoff Journal: Biol Sex Differ Date: 2011-12-12 Impact factor: 5.027