QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Tsai, A. C. Articles by Kelley, J. J. Search for Related Content PubMed PubMed Citation Articles by Tsai, A. C. Articles by Kelley, J. J.

Effect of Cholesterol Feeding on Hepatic Fatty Acid Synthesis and Serum and Tissue Enzyme Activities in Rabbits¹

Human Nutrition Program, School of Public Health, The University of Michigan, Ann Arbor, Michigan 48109

Effects of cholesterol-feeding on hepatic fatty acid synthesis, tissue lipid peroxidation, and the activity of certain enzymes were examined in rabbits. Rabbits were fed a stock diet supplemented either with 2% soy bean oil or with 2% soy bean oil and 1% cholesterol (dissolved in oil) for 102 days. The rate of lipid peroxidation was very low in the liver and aorta in both groups. Liver glutathione peroxidase, catalase, and superoxide dismutase activities were significantly lower in cholesterol-fed rabbits when expressed on a per g liver basis, but not on a per mg protein or per liver basis. Glutathione peroxidase activity in the aorta was reduced by cholesterol-feeding. Cholesterol-feeding did not influence the activity of glutathione peroxidase in the serum or superoxide dismutase in the aorta. Liver microsomal cytochrome P-450 and microsomal peroxidase activities were significantly lower in cholesterol-fed rabbits when expressed on a per g liver basis, but not on a per liver basis or per mg microsomal protein basis. The decrease in cytochrome c reductase activity was not significant. Cholesterol-feeding, however, significantly increased the rate of incorporation of [¹⁴C]glucose carbon into liver long-chain fatty acids in vitro. Liver glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activities were significantly increased by cholesterol-feeding when expressed on a per liver basis, but not on a per mg protein or per g liver basis. The study indicates that cholesterol-feeding enhances hepatic fatty acid synthesis and increases the total activities of liver NADPH-generating dehydrogenases, but had no effect on the total activity of other enzymes or microsomal parameters determined in rabbits.

KEY WORDS: • cholesterol-feeding • fatty acid synthesis • tissue lipid peroxidation • glutathione peroxidase • catalase • superoxide dismutase • microsomal cytochrome P-450

¹ The work was supported in part by a grant-in-aid from the Michigan Heart Association.

Manuscript received 4 May 1977.