Revista de Morfología y Anatomía

Neurodegenerative Changes in the Cerebral Cortex of Adult Wistar Rats Following Lead Induced Oxidative Damage

Abstract

Ajibade AJ* and Akinrinade SO

Lead is among the chemical compounds that have been reported to cause devastating problem worldwide. The primary site of action of lead is the central nervous system. This study investigated some effects of lead acetate on the cerebral cortex of adult Wistar rats. Thirty six adult Wistarrat of both sexes weighing between 120 g-250 g were randomly grouped into four groups of nine animals per group. Group A rats which was the control was maintained on standard feed and distilled water for 28 days, group B rats were treated with 10 mg/kg of lead acetate for 28 days, group C rats were treated with 20 mg/kg of lead acetate for 28 days and group D rats were also treated with 40 mg/kg of lead for 28 days. The lead acetate solution was administered orally on daily basis. The weights of the Wistar rats was recorded on weekly basis using a sensitive balance (before and during the weeks of administration). On the 28th day of the treatment the Wistar rats in group A, B, C and D were sacrificed by cervical dislocation, the brain was removed and weighed immediately using a sensitive balance, part of the brain was collected and homogenized for biochemical analysis for MDA.GSH and NO, the remaining part was then fixed in 10% formol calcium, the tissue was processed and sectioned at 5μm and stained with Haematoxylin and Eosin for histological study. The morphometric result showed that the mean body weights of the Wistar rats reduced significantly (P<0.05) in group B,C and D which received 10 mg/kg, 20 mg/kg and 40 mg/kg of lead acetate respectively as compared with Group A which reduced insignificantly (P>0.05). The brain weights in group B, C and D also decreased insignificantly (P>0.05) when compared with group A (control group). In the biochemical analysis there was statistically significant increase (p<0.05) in the level of Malondialdehyde (MDA) and Nitric Acid (NO) and statistically decreased level of Glutathione (GSH) in group B, C and D as compared with group A. Histological study of the cerebral cortex revealed that the cerebral cortical layers in group B, C and D appeared distorted and degenerated and in a dose dependent manner as compared with group A which shows a normal cerebral cortical architecture. This study concluded that lead has a neurotoxic effect on the cerebral cortex of adult Wistar rats which may adversely affect some cerebral functions