Lipid peroxide levels in tissues of live fish

Steady-state levels of lipid peroxide (LPO) in lateral muscles and liver of normal live fish, their elevation indeed by xenobiotics and the distribution in lipid class were studied using yellowtail Seriola quinqueradiata, red sea bream Chrysophrys major, carp Cyprinus carpio, sweet fish (or ayu) Plecoglossus altivelis, etc. LPO levels expressed in terms of meq/kg lipid, so to speak peroxide value (PV), vary in inverse proportion to the lipid contents; the higher the lipid content the lower the PV. Thus, PVs in live fish fluctuate with lipid contents. On the other hand, LPO levels expressed in terms of nmol/g tissue showed a steady-state reflecting physiological activity of tissue; 100-200 nmol/g tissue in liver and dark muscle, and lower than 50 nmol/g tissue in ordinary muscle. The levels was elevated by abdominal injection of CCl sub(4) and a bacterial culture. In lipids of wild yellowtail tissues, nearly the same total amounts of LPO were distributed in neutral lipid and phospholipid fractions.