s-0139 and Reperfusion-Injury

Recent evidence strongly suggests that endothelins (ETs) play an important role in the regulation of blood-brain barrier (BBB) functions. The aim of the present study was to evaluate the role of ETs on edema formation and BBB permeability change after cerebral ischemia/reperfusion.. We examined the brain tissue ET-1 content and evaluated the time and dose response of the therapeutic effects of the specific ET type A receptor (ET(A)) antagonist, S-0139, on brain edema formation, development of infarction, and disruption of BBB after 1 hour of middle cerebral artery occlusion (MCAO) in rats.. After 1-hour MCAO and reperfusion, the brain ET-1 content did not change during the first 3 hours, increased at 6 hours, and rose almost continuously over 48 hours in the ischemic region as well as in the ischemic rim. Rats infused with S-0139 (0.03 to 1.0 mg/kg per hour) during reperfusion showed dose-dependent and significant attenuation of the increase in brain water content 24 hours after reperfusion. When the infusion of S-0139 was begun after 10 minutes and 1 hour of reperfusion, the brain edema formation and infarct size were significantly attenuated. Furthermore, posttreatment with S-0139 significantly attenuated the increased Evans blue dye-quantified albumin extravasation and improved the mortality of animals after cerebral ischemia/reperfusion.. Our data demonstrate that infusion with S-0139, an ET(A) antagonist, results in significant reduction of brain injury and plasma extravasation after transient MCAO. Thus, ETs may contribute to cerebral ischemia/reperfusion injury at least partly by increasing the BBB permeability via ET(A)s.

Topics: Animals; Blood-Brain Barrier; Brain; Brain Chemistry; Brain Edema; Caffeic Acids; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelin Receptor Antagonists; Endothelin-1; Endothelins; Infarction, Middle Cerebral Artery; Ischemic Attack, Transient; Male; Neuroprotective Agents; Oleanolic Acid; Peroxidase; Rats; Rats, Wistar; Receptor, Endothelin A; Reperfusion Injury; Survival Rate; Time Factors; Water