EFFECT OF DELAYED ALBUMIN HEMODILUTION ON INFARCTION VOLUME AND BRAINEDEMA AFTER TRANSIENT MIDDLE CEREBRAL-ARTERY OCCLUSION IN RATS

The authors examined the effect of delayed high-concentration albumin therapy on ischemic injury in a highly reproducible model of middle ce rebral artery (MCA) occlusion in rats. Male Sprague-Dawley rats weighi ng 270 to 320 g were anesthetized with halothane and subjected to 120 minutes of temporary MCA occlusion induced by means of a poly-L-lysine -coated intraluminal nylon suture inserted retrograde via the external carotid artery into the internal carotid artery and MCA. The agent (2 0% human serum albumin [HSA]) or control solution (sodium chloride 0.9 %) was administered intravenously at a dosage of 1% of body weight imm ediately after suture removal following a 2-hour period of MCA occlusi on. The animals' neurological status was evaluated during MCA occlusio n (at 60 minutes) and daily for 3 days thereafter. The brains were per fusion-fixed, and infarct volumes and brain edema were determined. The HSA significantly improved the neurological score compared with salin e at 24 hours after MCA occlusion. The rats treated with HSA also had significantly reduced total infarct volume (by 34%) and brain edema (b y 81%) compared with saline-treated rats. There was a strong correlati on between hematocrit level and brain edema (p < 0.01), and between to tal infarct volume or brain edema and neurological score at 24, 48, an d 72 hours postinjury (p < 0.0002). These results strongly support the beneficial effect of delayed albumin therapy in transient focal ische mia and indicate its possible usefulness in treating patients with acu te ischemic stroke.