The objective of the study is to investigate the effects of chronic aluminum overload on rat liver function and its induction of pathological changes in metal ion levels and oxidative stress in hepatic tissues. Wistar rats were intragastrically administered aluminum gluconate (200 mg Al(3+)/Kg) once a day, 5 days a week, for 20 weeks. HE staining was used to visualize pathological changes in rat liver tissue. A biochemical method was adopted to detect ALT, AST, ALP, and GGT levels, as well as liver SOD activity and blood plasma MDA content. A plasma atomic emission spectrophotometer was used to detect Al, Mn, Fe, Zn, and Cu ion contents in liver tissue. Our results showed obvious vacuolar degeneration, granular degeneration, and spotty necrosis in chronic Al-overload rat hepatocytes. The levels of ALT, AST, ALP, and GGT were significantly increased. Liver SOD activity was significantly decreased, and MDA content was significantly increased. In Al-overload rat liver, Al, Mn, Fe, and Cu contents were significantly increased, and in Al-overload rat serum, Mn, Fe, Zn, and Cu contents were significantly decreased. However, the Al level in Al-overload rat serum was not significantly different from that in control rat serum. These results suggest that chronic aluminum overload causes obvious damage to rat liver and causes imbalances in Al, Mn, Fe, Zn, and Cu levels in rat liver and serum. Metal ion imbalance-related oxidative stress may be involved in the mechanism of chronic liver injury caused by aluminum overload.
Keywords: Chronic aluminum load; Histopathology; Liver function; Metal ions; Oxidative stress.