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.
|Original language||English (US)|
|Number of pages||14|
|State||Published - Apr 2008|
- Cerebral microcirculation
- Ischemia-reperfusion injury
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine