RESUMO
We studied the effects, at 10 and 30 min, of a single dose (10 mg kg(-1)) of lead chloride, administered by the intraperitoneal route, on the activities of acetylcholinesterase (AChE) and glutathione transferase (GSH-T) and on the concentrations of total and non-protein thiols in substantia nigra compacta (SNCO) and substantia nigra reticulata (SNRE), caudate putamen (CAU) and cerebral cortex (CC) from adult male rats in comparison with the effects of this metal at 24 and 72 h. The main immediate effects of lead consisted of decreased GSH-T activity and total and non-protein thiol concentrations in CAU and CC 10 min after administration. These effects were reversed after 30 min but with increased GSH-T activity in SNCO and AChE activity in SNRE along with diminished concentration of homogenate proteins in SNRE, CAU and CC. The GSH-T activity again was increased in SNCO but the AChE activity was decreased in CC 24 h after Pb administration; total and non-protein thiol concentrations were diminished but homogenate protein concentration was augmented in all areas. Finally, 72 h after Pb administration, AChE and GSH-T activities were decreased in CAU and CC, accompanied by an increased concentration of precipitate and supernatant proteins; supernatant protein concentration also was augmented in SNCO and SNRE; here, again, the concentrations of total and non-protein thiols were diminished and the homogenate protein concentration was augmented in all areas.