Effects of tocopherol deficiency on lipid metabolism in the arterial wall of rats on normal and high cholesterol diets.
The effects of dietary tocopherol deficiency on arterial wall enzymes involved in lipid synthesis and hydrolysis were studied in rats receiving normal diets and diets supplemented with 1% cholesterol. Arterial wall lipase and cholesterol esterase were associated with both the lysosome and microsome fractions, whereas acyl CoA synthetase, triglyceride synthesizing activity, cholesteryl ester synthesizing activity and cytidine diphosphatecholine-1,2-diacyl glycerol choline phosphotransferase (CPT) were found mainly in the microsomal fraction. When tocopherol was depleted from either the normal or high cholesterol diets, the following changes occurred in the arterial wall: (1) increase in thiobarbituric acid reactive substances; (2) decrease in lysosomal acid lipase and acid cholesteryl esterase; (3) decrease in the microsomal enzymes, acyl CoA synthetase, triglyceride synthesizing activity, cholesteryl ester synthesizing activity, neutral lipase and neutral cholesteryl esterase; and (4) increase in microsomal CPT. The results of these studies suggest that dietary tocopherol plays an important role in both lipid synthesis and degradation in the arterial wall, and the results may account for the accumulation of lipids and lipoperoxides in atherosclerotic lesions.
D000818:Animals; D001011:Aorta / Q000201:enzymology; D001158:Arteries / Q000378:metabolism*; D002791:Cholesterol, Dietary / Q000494:pharmacology*; D002798:Diacylglycerol Cholinephosphotransferase / Q000032:analysis; D050356:Lipid Metabolism; D008054:Lipid Peroxides / Q000096:biosynthesis; D008297:Male; D051381:Rats; D014810:Vitamin E / Q000097:blood; D014811:Vitamin E Deficiency / Q000378:metabolism*
D002791:Cholesterol, Dietary; D008054:Lipid Peroxides; D014810:Vitamin E; D002798:Diacylglycerol Cholinephosphotransferase