Cadmium’s effects on daily rhythm genes in rat brain’s hormone control areas and how melatonin influences this

Chronic exposure to cadmium decreased expression of clock genes in the hypothalamic-pituitary unit of rats.

• Cadmium treatment reduced hypothalamic Per 1 gene expression at both time intervals measured.
• Adenohypophysial Per 1 and Per 2 gene expression was decreased by cadmium at 09:00h.
• Hypothalamic Per 2 gene expression was also reduced by cadmium at 01:00h.
• Melatonin administration counteracted most cadmium effects, increasing expression of hypothalamic Per 2 and adenohypophysial Per 1 and Per 2 genes.

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