Hyperlipidemia in guinea-pigs induced by ascorbic acid deficiency. The effects of cholesterol, DL-ethionine and aflatoxin.

A study was made of hyperlipidemia caused by ascorbic acid deficiency and of the effects of cholesterol, DL-ethionine and aflatoxin on plasma lipoprotein fractions of normal and scorbutic guinea pigs. The plasma lipoprotein fractions of scorbutic animals showed a significantly higher level of pre-beta-lipoprotein and a lower level of alpha-lipoprotein. By adding DL-ethionine to the control group, the pre-beta-lipoprotein fraction was remarkably elevated and by adding cholesterol, the alpha-lipoprotein level was greatly reduced and the beta-lipoprotein level was increased. Addition of aflatoxin to the control diet resulted in a rather high concentration of alpha-lipoprotein and a low pre-beta-lipoprotein level. High concentrations of triglyceride and phospholipid were seen in the plasma of scorbutic guinea pigs. The probable cause of hyperlipidemia induced by ascorbic acid deficiency is partly retarded degradation of cholesterol resulting from impaired 7 alpha-hydroxylation, and partly that ascorbic acid deficiency may affect other enzyme systems that control triglyceride of phospholipid metabolism, such as lipoprotein lipase activity, or synthesis or breakdown of these enzymes.