ABSTRACT
OBJECTIVE: To investigate the effects of lead exposure and high fat diet on the hippocampal inflammatory factors and learning-memory in rats. METHODS: A total of 40 specific pathogen free male SD rats were randomly divided into control group,high fat diet group,lead exposure group,combine exposure group,10 rats in each group. Rats in control group were given regular diet and rats in high-fat diet group were given high-fat diet. Rats in lead exposure group were given regular diet and water with 400 mg/L lead acetate. Rats in combine exposure group were given high fat diet and water with 400 mg/L lead acetate. Body weight was measured every other week. The exposure period was 9 weeks. Morris water maze was applied to measure the learning-memory. The content of total cholesterol,triglyceride(TG),low density lipoprotein cholesterol(LDL) and high density lipoprotein cholesterol(HDL) in serum were detected by using microplate reader. The lead content of hippocampus was detected by inductively coupled plasma mass spectrometer. Enzyme-linked immuno sorbent assay was used to detect the content of tumor necrosis factor-α(TNF-α),interleukin(IL)-1β,IL-4,IL-6 and interferon-γ(IFN-γ). RESULTS: Beginning from the third week,the body weight of rats in high fat diet and combine exposure group were significantly higher than that in control group(P < 0. 05). In addition,the body weight of rats in combine exposure group were higher than that in lead exposure group(P < 0. 05). Escape latency and the frequency of crossing platform of rats in high fat diet group,lead exposure group and combine exposure group were significant changed compared with those in control group(P < 0. 05). The escape latency of rats in combine exposure group increased compared with those in high fat diet group and lead exposure group(P < 0. 05). In addition,serum TG and LDL content in high-fat diet group and combine exposure group increased and HDL decreased compared with the control exposure group and lead exposure group(P < 0. 05). Compared with the control group and high fat diet group,the content of lead in hippocampus of lead exposure group and combine exposure group substantially increased(P < 0. 05). The levels of TNF-γ,IL-6,IL-1β,IFN-γ of hippocampus in high fat diet group,lead exposure group and combine exposure group were significantly higher than those in control group(P < 0. 05). Besides,the levels of IL-4 of hippocampus in lead exposure group and combine exposure group were higher than that in control group(P < 0. 05). IL-1β content of rats hippocampus in combine exposure group was higher than that in high-fat diet group or lead exposure group(P < 0. 05). CONCLUSION: Combine lead and high-fat diet exposure can exert a synergy in decrease of learning-memory in rats. IL-1β might involved in the process of synergic neurotoxicity induced by lead and high fat diet.