Changes in Biochemical Parameters Related to Lipid Metabolism Following Lithium Treatment in Rat

Lithium is widely used in medicine as an anti-depressive drug. In spite of abundant literature, questions on the side effects of lithium ions are far from being answered. In this study, the effects of lithium on biochemical parameters related to lipid metabolism were investigated. Male Wistar rats were treated with different doses of lithium for a period of up to 60 days. Blood samples were collected and livers were removed for analysis. Lipid related parameters in plasma and livers were measured by standard methods. Epididymal fat pads were used to investigate the mechanism of lithium action on lipolysis. It is shown that the major effect of lithium is reduction of HDL-C concentration and the increase of LDL-C only in high doses. Lithium treatment led to a decrease in liver content of triglycerides but phospholipids increased significantly. Lithium also showed to inhibit lipoprotein lipase activity. This inhibitory effect is potentiated in the presence of citrate. Fat cell lipolysis is also inhibited by lithium, which is not reversed by alpha, and beta-receptor blockers indicating that lithium may exert its effect beyond these receptors. Lithium changes the metabolism of lipoproteins. The finding that lithium decreases HDL and increases LDL concentrations should be considered seriously, especially in patients using this drug for a long period