DIETARY VITAMIN-E LEVELS AFFECT OUTCOME OF PERMANENT FOCAL CEREBRAL-ISCHEMIA IN RATS

Background and Purpose-A supraphysiological amount of vitamin E in the standard diet of laboratory animals may provide partial protection ag ainst cerebral ischemic damage in stroke models. The aim of the presen t study was to test the effect of dietary vitamin E on infarct volume in rats subjected to permanent focal cerebral ischemia. Methods-Male W istar rats were raised on a vitamin E-deficient diet (n=10) or a contr ol diet containing 62.7 mg vitamin E/kg (n=11) for 13 to 16 weeks, fro m the age of 3 weeks. The left middle cerebral artery (MCA) was perman ently occluded by means of an intraluminal silicons-coated 3-0 suture. Blood flow in the left MCA territory was measured before and after oc clusion with laser Doppler flowmetry. The area of infarction was measu red in hematoxylin-eosin-stained brain sections by means of an image a nalysis system. The investigator was not aware of the vitamin E status of the rats. Results-Blood flow in the left MCA territory in the seco nd half hour after occlusion was 43+/-17% and 42+/-17% (mean+/-SD) of the baseline value in control and vitamin E-deficient rats, respective ly. The mean infarct volume, measured after 48 hours of survival, was 61+/-19 mm(3) in control rats and 137+/-76 mm(3) in vitamin E-deficien t rats (P=0.037). Conclusions-After permanent focal cerebral ischemia, the infarct is larger in vitamin E-deficient rats than in rats raised on a diet with the usual, supraphysiological amount of vitamin E. Thi s may have consequences for cerebral ischemia studies with experimenta l animals.