Effects of Lead Exposure on Nitric Oxide-associated Gene Expression in the Olfactory Bulb of Mice

Abstract

Lead (Pb) is known to have toxic effects on the brain; however, data regarding its specific toxic effects on the olfactory bulb are lacking. Therefore, we investigated the relationship between acute Pb exposure and alterations in gene expression associated with the nitric oxide signaling pathway in the olfactory bulb of mice. After administration of Pb (intraperitoneal injections of 1 or 10mg/kg Pb(CH(3)CO(2))(2) · 3H(2)O once per day for 4days), body weight, motor activity, and gene expression in the olfactory bulb of mice were examined. High doses of Pb resulted in significant decreases in body weight, but motor coordination was not significantly altered until 11days after the end of Pb treatment. The expression patterns of dimethylarginine dimethylaminohydrolase 1 (Ddah1), superoxide dismutase 1 (Sod1), and superoxide dismutase (Ccs) were increased, whereas expression of the Stratifin (Sfn) gene was significantly decreased following treatment with 10mg/kg Pb. The expression patterns of nitric oxide synthases at the mRNA and protein levels, however, were not significantly altered by treatment with 10mg/kg Pb. These findings indicate that Pb-induced neurotoxicity may be modulated in part by the expression of Ddah1, Sod1, Ccs, and Sfn in the olfactory bulb.