Consequences of subacute intratracheal exposure of rats to cadmium oxide nanoparticles

Abstract

Cadmium (Cd) is a metal used in various industrial applications, thereby causing exposure to Cd-containing fumes. The submicron-sized particles in the fumes represent an extra risk due to their high mobility within the organism and high surface area. Toxicity of Cd on the liver, kidney and bones is well known, but there are less data on its neurotoxicity. Here, male Wistar rats were treated for 3 and 6 weeks by intratracheal instillation of cadmium oxide nanosuspension. The body weight gain in treated rats was significantly decreased, and in the rats treated with high dose (0.4 mg/kg Cd daily), there was a significant increase in the weight of lungs and thymus. In this group, the spectrum of spontaneous cortical electrical activity was shifted to higher frequencies, the latency of sensory-evoked potentials was lengthened, and the frequency following ability of the somatosensory evoked potential was impaired—even without detectable Cd deposition in the brain. The data support the role of the nano-sized Cd in the causation of nervous system damage and show the possibility of modeling human neurotoxic damage in rats.