ABSTRACT
Objective Endothelin-1 (ET-1) is expected to be a new therapeutic target for cerebral ischemic stroke (CIS). The content of plasma is known to increase after stroke, but the changes in the brain remain unclear. The aim of this study was to investigate the expression and distribution of ET-1 and endothelin receptors (ETR) in the brain after CIS in rats and their relationship with related brain injury. Methods We established a model of middle cerebral artery occlusion (MCAO)-reperfusion in 12 male SD rats, 6 with nylon filament inserted through the left internal carotid artery (the ischemia-reperfusion [IR] group) and the other 6 without (the sham operation group). We observed the distribution of ET-1 and ETRs in different regions of the brain by immunohistochemistry. Results Compared with the sham operation group, the IR group showed significantly higher expressions of ET-1 in the cortex (0.107 ± 0.005 vs 0.230 ± 0.019, P < 0.05), caudate putamen (0.110 ± 0.028 vs 0.198 ± 0.008, P < 0.05) and hippocampus (0.101 ± 0.005 vs 0.183 ± 0.002, P < 0.05), ETR-A in the bilateral choroid plexus (0.086 ± 0.009 vs 0.131 ± 0.001, P < 0.05), pial vessels (0.063 ± 0.003 vs 0.132 ± 0.005, P < 0.05) and middle cerebral arteries (0.079 ± 0.003 vs 0.121 ± 0.008, P < 0.05), and ETR-B in the infarcted cortex (0.032 ± 0.003 vs 0.187 ± 0.025, P < 0.05) and hippocampus (0.029 ± 0.002 vs 0.226 ± 0.019, P < 0.05) of the ischemic hemisphere. Conclusion After cerebral IR, ET-1 and ETRs are selectively expressed in different brain regions, and their distribution may be related to IR-induced brain injury.