Inflammatory and hemodynamic changes in the cerebral microcirculation of aged rats after global cerebral ischemia and reperfusion.
Microcirculation
; 15(4): 297-310, 2008 May.
Article
em En
| MEDLINE
| ID: mdl-18464159
ABSTRACT
Effects of aging on inflammation and blood flow in the brain are unclear. Young (three to six months) and aged (19-22 months) male Brown Norway Fisher rats were used to compare (i) leukocyte function in nonischemic conditions and (ii) leukocyte function and hemodynamic changes after ischemia-reperfusion (I-R). In nonischemic studies, polymorphonuclear (PMN) CD11b expression and reactive oxygen species (ROS) production were measured with flow cytometry and PMN chemotaxis was measured with a Boyden chamber (+/-fMLP). In I-R studies, ischemia was induced by bilateral carotid artery occlusion and hypotension (20 minutes). During early reperfusion (30 minutes), leukocyte adhesion and rolling and blood-shear rates were measured using fluorescence microscopy. During late reperfusion (48 hours), mortality, neurological function, and leukocyte infiltration were measured. Stimulated PMN chemotaxis was increased in nonischemic aged rats (p < 0.05). In early reperfusion, there was a significant increase in leukocyte rolling and adhesion in the cerebral microcirculation and a significant decrease in shear rate in aged rats, compared to the young (p < 0.05). During late reperfusion, neurologic function was worse in aged vs. young rats (p < 0.05). These findings suggest that increased intravascular PMN adhesion and vascular dysfunction may contribute to poor neurologic outcome after cerebral I-R in the aged brain.
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Base de dados:
MEDLINE
Assunto principal:
Encéfalo
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Envelhecimento
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Traumatismo por Reperfusão
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Transtornos Cerebrovasculares
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Hemodinâmica
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article