Acute and subchronic effects of lead on the central and peripheral nervous systems in rats in combination with alcohol.

Humans are exposed, either simultaneously or sequentially, to various chemicals, including the neurotoxicants lead and ethanol. The aim of the present work was to investigate the changes in the spontaneous cortical activity (electrocorticogram; ECoG) and in the stimulus-dependent evoked potentials (EPs) recorded from rats pre-treated with alcohol and treated with lead acutely (intraperitoneally) or subchronically (by gavage). The measured parameters were spectral composition of the ECoG, amplitude and the latency of the stimulus-evoked cortical potential, as well as compound action potential amplitude, conduction velocity, and relative and absolute refractory period in a peripheral nerve. With subchronic lead and alcohol treatment, significant increase in the frequency of spontaneous activity and slight decrease in the EP amplitude were seen. In acute administration, EP amplitude increased and conduction velocity of the tail nerve decreased significantly. Our results showed that, in a combined exposure situation which is likely to happen also in humans, the known effects of neurotoxic heavy metals can be more severe.