Prolonged Exposure to Lead Lowers the Threshold of Pentylenetetrazole‐induced Seizures in Rats

Abstract

Summary:Purpose: The aim of this work was to study the effects of prolonged exposure to lead on the threshold of experimental seizures induced by pentylenetetrazole (PTZ).Methods: The 120 Wistar male rats were allocated randomly into four groups; (A) controls, and lead-treatment groups (B, C, and D) that received lead acetate in the drinking water for a period of 30 days at concentrations of 250, 500, and 1,000 ppm, respectively. After exposure, a trial of PTZ-induced seizures was conducted in all groups, and blood contents of lead were determined by atomic absorption spectrophotometry.Results: Blood lead contents increased in a dose-dependent manner. Time elapsed to develop the first myoclonic jerk and the tonic-clonic seizure was less in all lead-exposed groups than in controls. This effect was greater in the groups administered 500 and 1,000 ppm of lead. The required doses of PTZ to induce myoclonic jerks and tonic-clonic seizures were lower in leadexposed rats than in controls.Conclusions: We found a reduction in the threshold for seizures in rats whose blood contents of lead were similar to those of humans from some areas of urban centers with high levels of air pollution.

Thalidomide inhibits pentylenetetrazole-induced seizures

“…This effect was evident on the brainstem component of seizures responsible for the tonicclonic seizure [14], whereas the forebrain component, responsible for the myoclonic jerks, was not altered by the administration of thalidomide. This peculiar dichotomy in the prevention of epileptic discharges by thalidomide is in contrast with most other antiepileptic drugs and facilitating factors that interfere with variable intensity with both components of PTZ-induced seizures, the brainstem and the forebrain [15,16]. These findings suggest a singular inhibitory mechanism of the epileptic discharge produced by thalidomide.…”

Postnatal erythropoietin treatment mitigates neural cell loss after systemic prenatal hypoxic-ischemic injury

“…The seizure threshold was tested in adult rats using a PTZ (GABA antagonist) dose escalation paradigm 2. For each seizure grade from I to III, a significantly lower PTZ dose was required to induce seizures in rats after prenatal TSHI (n = 34), compared with sham controls (n = 41; Grade I: p = 0.012, Grade II: p = 0.02, Grade III: p = 0.03), indicating that the prenatal insult lowers the seizure threshold (Fig.…”

“…An escalating dose paradigm with PTZ was used to define the average dose necessary to induce seizures, or seizure threshold 2. Each rat was uniquely marked, sex was recorded, and rats were weighed on each testing day.…”

The cytotoxic effect of the NOS‐mediated oxidative stress in MCF‐7 cells after PbCl2 exposure

“…The health risk of Pb exposure draws attention because of its persistence and inherent processes of bioconcentration and bioaccumulation. The potential toxic effects of Pb on the nervous, cardiovascular, circulatory, hematologic, renal, skeletal, reproductive, immune, and endocrine systems have been documented extensively (Goyer, 1993;Arrieta et al, 2005;Bridges and Zalups, 2005;Mishra et al, 2006;Xi et al, 2012).…”