Dw. Morel et al., TREATMENT OF CHOLESTEROL-FED RABBITS WITH DIETARY VITAMIN-E AND VITAMIN-C INHIBITS LIPOPROTEIN OXIDATION BUT NOT DEVELOPMENT OF ATHEROSCLEROSIS, The Journal of nutrition, 124(11), 1994, pp. 2123-2130
New Zealand White rabbits were made hypercholesterolemic by feeding a
high cholesterol diet (10 g/kg diet) with or without added antioxidant
s. The antioxidants used were either probucol (10 g/kg) or vitamin E (
10 g/kg) plus vitamin C (0.6 g/kg). Serum cholesterol concentrations w
ere monitored as a function of time. At the end of 10 wk, serum and li
poprotein vitamin E concentrations, the extent of oxidation of lipopro
tein fractions (thiobarbituric acid reacting substances), the suscepti
bility of lipoprotein to oxidation in vitro (conjugated diene formatio
n) and the extent of atherosclerosis (aortic area stained by Sudan IV
and plague thickness) were measured. Rabbits fed diets supplemented wi
th vitamins E and C had markedly higher serum vitamin E concentrations
, marked vitamin E enrichment in all lipoprotein fractions, less oxida
tion in VLDL, and LDL and enhanced resistance of LDL to further in vit
ro oxidation, but did not have significantly less aortic atheroscleros
is. Rabbits given supplemental probucol likewise exhibited reduced oxi
dation of lipoproteins. However, aortic atherosclerosis in these anima
ls was significantly lower, as were serum cholesterol concentrations.
Inhibition of lipoprotein oxidation itself was not sufficient to reduc
e atherosclerosis in cholesterol-fed New Zealand White rabbits.