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

Abstract

Cadmium (Cd2+) is one of the most important environmental contaminants and acts as an endocrine disruptor. Previously, we have demonstrated that the simultaneous administration of Cd2+ 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 Cd2+ (5 parts per million [ppm], 30 days) were treated with Mel or without the metal during the next 1 or 2 months. Cd2+ 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 Cd2+. This effect was also observed 1 month after metal removal. The Cd2+-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 Cd2+ intoxication become evident only after a certain period of metal accumulation, these results show that metal removal is enough to reverse Cd2+ effects in anterior pituitary gland and bring to light the relevance of moving away the individual from the contamination source.