[The effect of dopamine injected into the lateral brain ventricle on flash visual evoked potential (FVEP) after...

Earlier studies demonstrated that exposure, especially prenatal, of mammalians to cadmium (Cd) results in disorders of visual evoked potentials (FVEP). The purpose of this study is to find out any influence of cadmium intoxications on the effect of dopamine (DA) on FVEP.

18 Wistar albino rats in 3-6 months of age were divided into 3 groups: control (drinking tap water only), prenatal exposure of 5 ppm, and 50 ppm Cd. Flash visual evoked potentials (FVEP) were recorded before and after injections of dopamine (DA) 100 and 200 nmols into the lateral brain ventricle. The amplitude and latency of N1 and P2 were statistically analysed by the test of t-Student. p < 0.05 was used to indicate significant difference.

There were no statistical differences of mean latency of P2 waves between initial records of FVEP and after both doses of DA in all observed groups. The amplitudes of both waves increased after DA injections compared to initial values in all groups. The differences were statistically significant. The mean latencies of N1 peak were prolonged after both DA doses (106-109%) compared to the initial records (100%) in the control group; however, there were no changes of it in the Cd-treated groups before and after DA injections.

Cadmium blocked the dopamine effect on the latencies of N1 and P2 of FVEP (because it prolonged them alone); however, cadmium increased the stimulative effect of dopamine on their amplitudes.