Cadmium effects on brain acetylcholinesterase activity and antioxidant status of adult rats: modulation by zinc, calcium and L-cysteine co-administration.

We have previously reported that cadmium (Cd) as 3CdSO4 . 8H2O decreases rat brain total antioxidant status and L-cysteine (Cys) has a protective effect against it. The aim of the present study was to investigate the effects of subacute Cd administration, either alone or (almost simultaneously) with zinc (Zn), calcium (Ca) and Cys, on brain acetylcholinesterase (AChE) activity and brain total antioxidant status in male adult rats. All substances were administered intraperitoneally. Cadmium (1 mg/kg/day for 14 days) increased AChE activity (+46%; P<0.001) and decreased total antioxidant status (-29%; P<0.001). Zinc and Ca (both 1 mg/kg/day for 14 days) increased AChE activity (+18%; P<0.01 and +53%; P<0.001) and caused no changes on rat brain total antioxidant status. L-Cysteine (7 mg/kg/day for 14 days) impressively increased AChE activity (+185%; P<0.001) and augmented total antioxidant status (+26%; P<0.001). In the groups of Zn+Cd, Ca+Cd and Cys+Cd co-administration, AChE activity remained high (+42%; P<0.001, +41%; P<0.001 and +141%; P<0.001 respectively), while total antioxidant status returned to the saline control levels. L-Cysteine given before a toxic dose of Cd (5 mg/kg) resulted in high AChE activity (+85%; P<0.001), a total antioxidant status similar to the control values, and survival of the treated rats. In conclusion, Cd increased brain AChE activity and decreased brain total antioxidant status of adult male rats. Zinc, Ca and Cys, given just before Cd administration, modified the Cd-induced effects and restored rat brain total antioxidant status to the control levels.