Manganese-induced effects on cerebral trace element and nitric oxide of Hyline cocks.

Exposure to Manganese (Mn) is a common phenomenon due to its environmental pervasiveness. To investigate the Mn-induced toxicity on cerebral trace element levels and crucial nitric oxide parameters on brain of birds, 50-day-old male Hyline cocks were fed either a commercial diet or a Mn-supplemented diet containing 600, 900, 1,800 mg kg(-1). After being treated with Mn for 30, 60, and 90 days, the following were determined: the changes in contents of copper (Cu), iron (Fe), zinc (Zn), calcium (Ca), selenium (Se) in brain; inducible nitric oxide synthase-nitric oxide (iNOS-NO) system activity in brain; and histopathology and ultrastructure changes of cerebral cortex. The results showed that Mn was accumulated in brain and the content of Cu and Fe increased. However, the levels of Zn and Se decreased and the Ca content presented no obvious regularity. Exposure to Mn significantly elevated the content of NO and the expression of iNOS mRNA. Activity of total NO synthase (T NOS) and iNOS appeared with an increased tendency. These findings suggested that Mn exposure resulted in the imbalance of cerebral trace elements and influenced iNOS in the molecular level, which are possible underlying nervous system injury mechanisms induced by Mn exposure.