Reduction of experimental myocardial infarct size by oral administration of alpha tocopherol.
OBJECTIVE
The aim was to determine whether high dose dietary vitamin E could improve myocardial resistance to ischaemia and reperfusion. Vitamin E is an important physiological antioxidant which can be accumulated to high levels in the myocardium, without toxicity, by chronic dietary supplementation.


METHODS
Subjects were fed a standard laboratory feed and water ad libitum for 10 d, plus either d-alpha-tocopoheryl acetate 200 IU.kg-1.d-1 orally (vitamin E group), or no supplement (control group). The animals then underwent either 60 or 180 min of left anterior descending coronary artery ligation, followed by 6 h reperfusion. The area at risk was identified by colloidal carbon, and necrosis by triphenyl tetrazolium chloride and light microscopy.


METHODS
Studies were performed on New Zealand white rabbits weighing approximately 3.5 kg.


RESULTS
In the 60 min ligation study, the control group had 30.5 (SD 4.0)% necrosis of the area at risk but the vitamin E group had no necrosis (n = 5 per group, p less than or equal to 0.0001). In the 180 min ligation study, the control group had 74.1 (11.5)% necrosis of the area at risk whereas the vitamin E group had 23.1 (7.2)% (n = 5 per group, p less than or equal to 0.0001).


CONCLUSIONS
High dose dietary supplementation with vitamin E can improve myocardial tolerance to ischaemia and reperfusion, significantly reducing myocardial infarct size.
Axford-Gatley
R A
RA
Cardiovascular Research Laboratory, Toronto General Hospital, Ontario, Canada.
Wilson
G J
GJ
D000284:Administration, Oral; D000818:Animals; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000473:pathology; D011817:Rabbits; D014810:Vitamin E / Q000494:pharmacology / Q000627:therapeutic use*
D014810:Vitamin E