Lipid peroxidation and its protective mechanism during developmental stage in rat.

The concentration of lipoperoxides in liver tissue was extensively high in the fetus and early newborn, but it decreased sharply thereafter. However, the concentrations of lipoperoxides in the blood and lung tissue were low in the fetal period, but increased after birth reaching a peak after about 10 days of life. Then they gradually decreased with development. The activities of enzymes such as superoxide dismutase, catalase and glutathione peroxidase together with the concentration of alpha-tocopherol (vitamin E) were extremely low in the fetal and early newborn periods, but increased gradually with development.