Lipid Peroxidation in Choline-Methionine Deficiency

Abstract
A deficiency of choline and methionine is hepatocarcinogenic and is associated with an apparent increase in lipid peroxidation. In this study the susceptibility of microsomes and nuclei to ferritin-dependent lipid peroxidation is examined together with the status of the peroxidation- protective systems. Choline-methionine deficiency caused an increase in Se-independent GSH peroxidases (GSH transferase subunit 2) and membrane vitamin E but a decrease in Se-dependent GSH peroxidase and microsomal GSH peroxidase activity. Choline-methionine deficient microsomes and nuclei were 4-fold more susceptible to lipid peroxidation induced in vitro by physiological concentrations of ferritin/ascorbate/ADP; and the peroxidation was less effectively inhibited by GSH and soluble GSH peroxidases than controls. The results indicate that a decreased level of Se-dependent and membrane GSH peroxidases is involved in the increase in lipid peroxidation observed in choline-methionine deficiency.