Protective effects of selenium and zinc on changes in catecholamine levels of brain regions in lead intoxified rat.

Lead is a common environmental toxic element for almost all biological systems. The nervous system is the primary target for the lead exposure. In the past few years, increasing considerations have been given to investigate the interaction occurring between toxic metals and some essential metals including Se and Zn with Pb. It has been shown that some trace elements could reverse the toxicity of lead on tissue functions. In this study the protective effects of Zn and Se on lead toxicity were investigated. Results of short time study showed that, intrapritoneal administration of Pb (13.5 mg kg(-1)) daily for 2 weeks reduced the catecholamine levels of cortex by 25, mid-Brain by 21 and cerebellum by 25.6%, respectively. Administration of the same amount of lead in combination with either Zn (0.5 mg kg(-1)) or Se (0.4 mg kg(-1)) reduced catecholamine levels of cortex by 8.3 and 18.3, mid-brain by 6, 10.9 and cerebellum 23, 6% respectively. Daily administration of lead alone (4 mg kg(-1)) for 60 days reduced catecholamine level of cortex by 27.4 and mid-Brain by 47.8 and cerebellum by 39%, respectively. When the same amount of lead in combination with Zinc (0.5 mg kg(-1)) and/or Se (0.4 mg kg(-1)) was administration daily for 60 days, results showed that catecholamine level of cortex was reduced by 9, 20 and mid-brain by 22.6, 29 and cerebellum 25, 16%, respectively. It is concluded that lead reduced catecholamine levels in different brain regions and Zn or Se might be able to reverse this reduction and protect brain function to some extent from lead toxicity.