A study on electrophysiological effects of subchronic cadmium treatment in rats

Male Wistar rats were treated for 4, 8 and 12 weeks with 3.5, 7.0 or 14.0 mg/kg cadmium (in the form of cadmium chloride) by gavage. Changes induced in certain electrophysiological parameters-electrocorticogram frequency; latency and duration of cortical sensory evoked potentials; conduction velocity and relative and absolute refractory periods of a peripheral nerve-were analyzed. On the electrocorticogram, increased frequency was seen. Lengthened latency and duration of the cortical evoked potentials, as well as lowered conduction velocity and increased refractory periods in the peripheral nerve, were observed. These changes seemed to increase with the dose and the treatment time and were statistically significant mainly in the highest dose groups following 12 weeks of treatment. The results show that subchronic, low-level exposure by cadmium affects the rat's spontaneous and evoked bioelectric activity and point at the possible consequences in exposed humans.