Alterations in Peripheral Nerve Conduction Velocity in Low and High Lead Exposure: An Animal Study

Abstract

To evaluate the effects of blood and nerve lead (BPb, NPb) concentrations on peripheral nerve conduction velocity (NCV), we measured maximal motor nerve conduction velocity in the sciatic nerve and its posterior tibial branch in forty 21-week-old male Wistar rats, which were given drinking water containing lead acetate at concentrations of 0.1, 0.5, 1.0 and 2.0% for 15 weeks (lead groups, ten rats for each dose); and in ten sex-and age-matched Wistar rats (control group), which were given drinking water free of lead acetate for the same period. NCV and BPb were significantly different between the rats given the smallest dose of lead acetate (0.1%) and the control group (p<0.05) while, on the other hand, no significant differences in NPb and body weight (BW) were observed between the two groups (p>0.05). With further increases in the dose of lead acetate, no significant changes were found in NCV and BW in each lead group; NPb was significantly higher in the 0.5% than in the 0.1% lead group. NCV was significantly correlated with BPb in all the fifty rats examined (lead and control groups combined, p<0.05), but not correlated with NPb and BW. These results suggest that the alteration in NCV is closely related to the change in BPb; NCV decreases most markedly at a lower level of BPb and the diminution rate of NCV decreases progressively as BPb increases.