Cadmium induced-oxidative stress in pituitary gland is reversed by removing the contamination source.

Cadmium (Cd(2+)) is one of the most important environmental contaminants and acts as an endocrine disruptor. Previously, we have demonstrated that the simultaneous administration of Cd(2+) and melatonin (Mel) in drinking water impaired metal-induced oxidative stress in rat anterior pituitary gland. The aim of this study was to investigate if a treatment started after the toxic manifestations of Cd( 2+) became evident could reverse the effects of the metal. Animals exposed to Cd(2+) (5 parts per million [ppm], 30 days) were treated with Mel or without the metal during the next 1 or 2 months. Cd(2+) exposure increased the expression of heme oxygenase-1 (HO-1), a biomarker of oxidative stress, and an a posteriori Mel treatment reversed oxidative stress induced by Cd(2+). This effect was also observed 1 month after metal removal. The Cd(2+)-induced increase in metallothionein-1 (MT-1) and nitric oxide synthase 1 (NOS1) expression were also reversed by metal removal. In addition, serum prolactin and luteinizing hormone levels affected by Cd( 2+) exposure were normalized. Considering that the manifestations of Cd(2+) intoxication become evident only after a certain period of metal accumulation, these results show that metal removal is enough to reverse Cd(2+) effects in anterior pituitary gland and bring to light the relevance of moving away the individual from the contamination source.