PROTECTION OF ZINC ON HIPPOCAMPAL SS AND SS mRNA POSITIVE NEURONS IN LEAD-EXPOSE D RATS

Objective: To investigate the protective effect of zinc on learning and memory of lead-exposed rats and hippocampal SS and SS mRNA neurons. Met hods: Wistar rats were exposed to 6.15 mmol/L lead acetate solution or 6.15 mmol/L lead acetate and 3.10 mmol/L zinc sulfate solution for three months, and the learning and memory ability was studied with Y-maze test. The blood and hippocampal lead concentration were measured with atomic absorption spectrometry and the number of hippocampal SS and SS mRNA positive neur ons were observed with immunohistochemistry and in situ hybridization respectively. Results: Compared with the control and lead-zinc group, the learning and memory ability of lead-exposed rats was significantly decreased(P0.05); the blood and hippocampal lead content in lead-zinc group, the blood and hippocampal lead content in lead-exposed rats was significantly increased(P0.01); the number of SS and SS mRNA positive neurons in CA 1 a nd CA 3 area of lead-exposed rats were obviously decreased (P0.05). But no significant difference was found between the control and lead-zinc group in CA 1 and CA 3 area. Conclusion: The effects of lead on learning and memory might be related to the changes of SS and SS mRNA neurons in different subfields of hippocampus in lead-exposed rats, and zinc might play an important role in preventing from lea d-induced damages.