Nervous system effects of dissolved and nanoparticulate cadmium in rats in subacute exposure.

Cadmium, a toxic heavy metal with various applications in technology, can affect people both by environmental (foodborne) and occupational (inhalation) exposure and can cause nervous system damage. To model this, rats were subacutely treated either with CdCl(2) solution per os (3.0 mg kg(-1) b.w.) or nanoparticulate CdO(2) (particle size ca 65 nm) by intratracheal instillation (0.04 mg kg(-1) b.w.) alone or in sequential combination. Nervous system effects were observed at different levels of function (open field behavior, cortical electrical activity, nerve action potential) and some general toxicological indicators were also measured. Three weeks of oral plus one week of intratracheal exposure caused significant reduction of body weight gain and open field motility. Lengthening of latency of sensory evoked potentials, observed in all treated rats, was also the most significant in the group receiving oral plus intratracheal treatment. Conduction velocity of the tail nerve was likewise decreased in all treated groups. Several of the effects pointed to a potentiating interaction between the two forms of Cd. Modeling environmental and occupational Cd exposure by oral and intratracheal application in rats was feasible, with results suggesting serious negative health effects in humans suffering such a combined exposure.