changes in liver contents of lipid fractions following titanium exposure

the potential to cause tissue damage by metal ions is the matter of widespread investigation. titanium salts are widely used in industry for ceramic painting, in pharmacy for tablet coating and making chemical sunscreens and in medicine as photo catalysts with bactericidal activity. this may address the idea that the exposure to these salts could play a role in metabolic disorders. in this study the effect of ti on liver contents of lipid fractions was investigated. male wistar rats (200-250 g) were used for the experiments. groups of animals were injected for 10 days with 2.5 mg/kg of titanium chloride, as acute dose and for 30 and 60 days with 0.75 mg/kg as chronic doses. at the end of the experimental period animals were anaesthetized, the abdomens were opened and the livers were perfused with appropriate buffer. livers were then removed immediately and used fresh or kept frozen until the analysis. livers were then homogenized and their contents of triglycerides and phospholipids were determined. blood samples were also collected before killing to measure the lipid levels. titanium led to a significant increase in phospholipid content of the liver (about 66 %) whereas triglycerides decreased by about 25 to 30 percent in all treated animals. titanium also reduced plasma free fatty acids and triglycerides significantly but cholesterol and ldl levels were increased in all treated animals. lipoprotein lipase activity was also inhibited in titanium treated animals. in conclusion this study is significant because it shows that chronic inhalation or exposure to titanium at workplaces is associated with changes in liver lipid metabolism. plasma lipid-related parameters were also affected. although less information is available concerning the mechanism of toxicity but the induction of reactive oxygen species production may be responsible for this effect.