K. Washida, M. Ihara, Keiko Nishio
Aug 1, 2010
Citations
2
Influential Citations
108
Citations
Quality indicators
Journal
Stroke
Abstract
Background and Purpose— The effect of telmisartan, an angiotensin II Type 1 receptor blocker with peroxisome proliferator-activated receptor-&ggr;-modulating activity, was investigated against spatial working memory disturbances in mice subjected to chronic cerebral hypoperfusion. Methods— Adult C57BL/6J male mice were subjected to bilateral common carotid artery stenosis using external microcoils. Mice received a daily oral administration of low-dose telmisartan (1 mg/kg per day), high-dose telmisartan (10 mg/kg per day), or vehicle with or without peroxisome proliferator-activated receptor-&ggr; antagonist GW9662 (1 mg/kg per day) for all treatments for 30 days after bilateral common carotid artery stenosis. Cerebral mRNA expression of monocyte chemoattractant protein-1 and tumor necrosis factor-&agr; was measured 30 days after bilateral common carotid artery stenosis, and postmortem brains were analyzed for demyelinating change with Klüver-Barrera staining and immunostained for glial, oxidative stress, and vascular endothelial cell markers. Spatial working memory was assessed by the Y-maze test. Results— Mean systolic blood pressure and cerebral blood flow did not decrease with low-dose telmisartan but significantly decreased with high-dose telmisartan. Low-dose telmisartan significantly attenuated, but high-dose telmisartan provoked, spatial working memory impairment with glial activation, oligodendrocyte loss, and demyelinating change in the white matter. Such positive effects of low-dose telmisartan were partially offset by cotreatment with GW9662. Consistent with this, low-dose telmisartan reduced the degree of oxidative stress of vascular endothelial cells and the mRNA levels of monocyte chemoattractant protein-1 and tumor necrosis factor-&agr; compared with vehicle. Conclusions— Anti-inflammatory and antioxidative effects of telmisartan that were exerted in part by peroxisome proliferator-activated receptor-&ggr; activation, but not its blood pressure-lowering effect, have protective roles against cognitive impairment and white matter damage after chronic cerebral hypoperfusion.