AJP - Heart and Circulatory Physiology, Vol 256, Issue 6 1539-H1545, Copyright © 1989 by American Physiological Society
Lipid peroxidation and altered vascular function in vitamin E-deficient rats
C. A. Hubel, K. C. Griggs and M. K. McLaughlin
Department of Obstetrics and Gynecology, University of Vermont College of Medicine, Burlington 05405.
Female rats deprived of dietary vitamin E for 35 wk postweaning were
analyzed for changes in vascular function. A functional state of vitamin E
deficiency was indicated by a marked increase in spontaneous hemolysis of
washed red cells by 22 wk of feeding. Elevated thiobarbituric acid-reactive
material in aorta, liver, and plasma samples from vitamin-E deficient rats
indicated increased lipid hydroperoxide formation. Systolic blood pressures
and heart rates measured biweekly were unaltered by diet. Before being
killed, the rats were catheterized and allowed to recover from anesthesia
(methohexital sodium ip). The pressor response to graded doses of
angiotensin II was significantly increased in the vitamin E-deficient group
relative to its control. Isolated superior mesenteric artery segments from
vitamin E-deficient rats demonstrated significantly decreased relaxation
responses to acetylcholine. In contrast, artery contractile responses to 50
mM potassium and to graded doses of extracellular calcium did not differ,
indicating that contractile capability was maintained. Surface blebbing of
the femoral artery endothelium was observed by scanning electron
microscopy. These data support a proposed link between lipid peroxidation
and development of altered vascular function.
