BACKGROUND AND PURPOSE: We studied the anion transport inhibitor L-644,711, which is known to reduce astrocyte swelling and excitotoxin release in primary astrocyte culture, in two models of thromboembolic stroke to assess its capacity to influence ischemic brain injury. METHODS: New Zealand White rabbits were used in this study. The two models include autologous clot embolized to the brain via the carotid artery, with one model using a transient period of systemic hypotension. Cerebral blood flow was determined by the hydrogen clearance method, intracranial pressure was measured with a fiberoptic transducer, and infarct size was assessed with triphenyltetrazolium chloride staining of the coronally sectioned brain. Both models received a 2-hour infusion of L-644,711 (total dose, 12 mg/kg) beginning 20 minutes before embolization. RESULTS: In both the normotensive (p less than 0.01) and the hypotensive (p less than 0.05) model, treatment with L-644,711 resulted in a significant reduction in infarct size and a significant improvement in regional cerebral blood flow (p less than 0.03, normotensive model, and p less than 0.05, hypotensive model). Raised intracranial pressure, unique to the hypotensive model, was abolished by the administration of L-644,711 (p less than 0.05). A hyperglycemic response associated with embolization, also unique to the hypotensive model, was significantly reduced by the administration of L-644,711 (p less than 0.05). CONCLUSIONS: The ability of L-644,711 to limit brain injury in two related models of thromboembolic stroke suggests a potential therapeutic role for anion channel blockers in cerebral ischemia.
BACKGROUND AND PURPOSE: We studied the anion transport inhibitor L-644,711, which is known to reduce astrocyte swelling and excitotoxin release in primary astrocyte culture, in two models of thromboembolic stroke to assess its capacity to influence ischemic brain injury. METHODS: New Zealand White rabbits were used in this study. The two models include autologous clot embolized to the brain via the carotid artery, with one model using a transient period of systemic hypotension. Cerebral blood flow was determined by the hydrogen clearance method, intracranial pressure was measured with a fiberoptic transducer, and infarct size was assessed with triphenyltetrazolium chloride staining of the coronally sectioned brain. Both models received a 2-hour infusion of L-644,711 (total dose, 12 mg/kg) beginning 20 minutes before embolization. RESULTS: In both the normotensive (p less than 0.01) and the hypotensive (p less than 0.05) model, treatment with L-644,711 resulted in a significant reduction in infarct size and a significant improvement in regional cerebral blood flow (p less than 0.03, normotensive model, and p less than 0.05, hypotensive model). Raised intracranial pressure, unique to the hypotensive model, was abolished by the administration of L-644,711 (p less than 0.05). A hyperglycemic response associated with embolization, also unique to the hypotensive model, was significantly reduced by the administration of L-644,711 (p less than 0.05). CONCLUSIONS: The ability of L-644,711 to limit brain injury in two related models of thromboembolic stroke suggests a potential therapeutic role for anion channel blockers in cerebral ischemia.
Authors: Renée E Haskew-Layton; Alena Rudkouskaya; Yiqiang Jin; Paul J Feustel; Harold K Kimelberg; Alexander A Mongin Journal: PLoS One Date: 2008-10-28 Impact factor: 3.240