title: Effect of vitamin E on lead exposure-induced learning and memory impairment in rats.
abstract: Chronic lead (Pb(2+)) exposure has been associated with learning and memory impairments, whereas vitamin E improves cognitive deficits. In this study, using a passive avoidance learning model in rats, we investigated the effects of vitamin E on Pb(2+) exposure-induced learning and memory impairments in rats. In the present study, 56 Wistar male rats (weighting 230-250g) were divided into eight groups (n=7). The Pb(2+) exposure involved gavages of lead acetate solution using three different doses (0.05%, 0.1%, and 0.2%) and the vitamin E consisted of three different doses (10, 25, 50μg/rat) for 30days. After the 30-day period, the rats were tested using a passive avoidance task (acquisition test). In a retrieval test conducted 48h after the training, step through latency (STL) and time in the dark compartment (TDC) were recorded. The statistical analysis of data was performed using ANOVA followed by Tukey's post hoc analysis. In all cases, differences were considered significant if p<0.05. The results of the present study showed that chronic exposure to high doses of Pb(2+) significantly increased both the number of trails required for learning and the TDC, whereas it decreased the STL in the passive avoidance test. Administration of vitamin E ameliorated the effects of Pb(2+) on animal behavior in the passive avoidance learning and memory task. Our results indicate that impairments of learning and memory in Pb(2+)-exposed rats are dose dependent and can be inhibited by antioxidants such as vitamin E.
authors.affiliation: Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; Department of Biology, Islamic Azad University of Hamadan, Hamadan, Iran.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Khodamoradi
authors.affiliation: Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran. Electronic address: alirezakomaki@gmail.com.
authors.forename: Alireza
authors.initials: A
authors.lastname: Komaki
authors.affiliation: Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Iraj
authors.initials: I
authors.lastname: Salehi
authors.affiliation: Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Siamak
authors.initials: S
authors.lastname: Shahidi
authors.affiliation: Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Abdolrahman
authors.initials: A
authors.lastname: Sarihi
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D003623:Dark Adaptation / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D007854:Lead / Q000633:toxicity*; D007859:Learning Disabilities / Q000139:chemically induced* / Q000188:drug therapy*; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced* / Q000188:drug therapy*; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects; D012153:Retention, Psychology / Q000187:drug effects; D013997:Time Factors; D014810:Vitamin E / Q000627:therapeutic use*
chemical_list: D014810:Vitamin E; D007854:Lead
keywords: Antioxidants; Lead acetate; Learning; Memory; Passive avoidance; Rat; Vitamin E