Lead induced thiamine deficiency in the brain decreased the threshold of electroshock seizure in rat.

Many neurological disorders that occur frequently in lead intoxicated animals, have also been observed in thiamine deficient animals. To test whether lead intoxication could decrease the thiamine status and thresholds of electroshock seizure in rats, 3-week-old Wistar rats were treated with lead or lead plus thiamine. For comparison, a thiamine deficient group was included. Thiamine contents and transketolase activity, one of the thiamine dependent enzymes in the brain regions were significantly lowered by lead intoxication and thiamine deficiency. In both cases, thresholds of the electroshock seizure were significantly decreased. Thiamine supplementation reversed these signs and decreased the brain lead concentration in the lead treated group. The results from the present study suggest that the increased seizure susceptibility induced by lead intoxication in rats may be mediated at least in part through the changes of thiamine status.