Changes in lipid peroxide and alpha-tocopherol levels of pregnant serum lipoproteins (author's transl)

Lipid peroxides act harmfully on cell membranes to result in cellular dysfunction. On the other hand, vitamin E (VE) having antioxidant effect is considered to protect the generation of lipid peroxides. In this study, the changes in the levels of lipid peroxides and VE of pregnant sera were followed clinically and biochemically in relation to lipoprotein metabolism. The results obtained were as follows. 1) Lipoprotein metabolism in pregnancy was characterized by an increase in very low density lipoprotein (VLDL) which is a major carrier of triglyceride. The amount of VLDL in pre-eclamptic subjects increased more than that of normal gravidas. The ratios of HDL cholesterol/LDL cholesterol of pre-eclamptic subjects were significantly (p less than 0.01) low levels compared with those of non-gravidas. 2) The contents of lipid peroxides and alpha-tocopherol (alpha-toc) in each serum lipoprotein fraction were also elevated in pregnant subjects. Lipid peroxide levels in HDL fraction of pre-eclamptic subjects were significantly (p less than 0.005) higher than those of normal gravidas. On the contrary, the levels of alpha-toc in HDL fraction of pre-eclamptic subjects were significantly (p less than 0.005) lower than those of normal gravidas. 3) As a result of examining the correlationship between the levels of lipid components and those of lipid peroxides and alpha-toc in each lipoprotein fraction of pregnant sera, both levels of lipid peroxides and alpha-toc were positively correlated with those of major lipid components in VLDL and LDL fractions, while no significant correlation was found in HDL fraction. Also in VLDL fraction, the level of lipid peroxides was positively correlated with that of alpha-toc whereas in HDL fraction the former tends to correlate reversely with the latter. From the above observation, it is worthwhile to study on HDL fraction which is associated with cell membrane lipids and received less influence of the amounts of serum lipids, when the damage with lipid peroxides under pregnancy accompanied of hyperlipemia is examined in relation to alpha-toc.