Alteration and recovery of the antioxidant system induced by sub-chronic exposure to microcystin-LR in mice: Its relation to liver lipid composition

Abstract

The effects of MC-LR on antioxidant system in liver and kidney and its effects on hepatic lipid composition after prolonged exposure to sublethal doses of microcystins(MCs) was studied in mice. Mice were treated i.p. with 25 ug of MC-LR/kg body weight or saline solution every 2 days for a month (inflictive stage), then progression or recovery was studied for 1 and 2 months of wash-out. During the inflictive stage, MC-LR induced oxidative damage and significant changes in liver lipids of treated mice compared with control mice. A clear dependence of the enzyme defense system was demonstrated with reduced glutathione and a-tocopherol availabilities and a concomitant elevation in NOx production. Sub-chronic MC-LR toxicosis produced alterations in lipid components that included a decreased EFA/non EFA, SFA/PUFA, and n-3/n-6 ratios all of which exhibited a pattern of slow recovery during the recovery periods.