【摘要】 目的　通过研究铅对大鼠海马一氧化氮合酶 (NOS)活力及表达的影响 ,分析海马不同亚区NOS活力变化与铅对海马长时程增强 (LTP)影响的关系。方法　Wistar大鼠采用饮水加 2 0、2 0 0、2 0 0 0 μg/ml醋酸铅 (PbAc)方法染毒 3个月后 ,用Y 迷宫法测试大鼠神经行为的改变 ;用原子吸收法测定血液与海马中铅的含量 ;用NADPH 黄递酶 (NADPH d)组化法和免疫组化法检测海马NOS的活力及表达情况。结果　 3个染铅组大鼠学习、记忆能力均比对照组明显下降 ;2 0 0 μg/ml和 2 0 0 0μg/mlPbAc大鼠血液和海马铅含量为 (370 .84± 6 9.89)、(10 11.6 2± 5 9.5 4)ng/g ,明显高于对照组 ,差异有显著性 (P <0 .0 5 ) ;NADPH d组化显示 ,2 0 0 μg/ml和 2 0 0 0 μg/mlPbAc大鼠海马CA1区NOS阳性神经元数 (5 1.5 9± 6 .30和 47.2 7± 6 .87)均明显少于对照组 (5 8.92± 5 .6 1) ,差异有显著性 (P <0 .0 5 ) ;免疫组化结果显示 ,2 0 0 0 μg/mlPbAc组大鼠海马CA1区神经元型NOS(nNOS)阳性神经元数(4 9.5 6± 6 .70 )明显少于对照组 (6 4.5 4± 12 .46 ) ,差异有显著性 (P <0 .0 5 )。各组大鼠海马CA3区NOS及nNOS阳性神经元数无明显改变。结论　铅对大鼠海马LTP的影响可能与染铅后海马各区NOS的不同变化有关更多还原

【Abstract】 Objective To investigate the effect of lead on the activity and expression of nitric oxide synthase(NOS) and relationship between the effects of lead on long term potentiation(LTP) in hippocampus and changes of NOS in subfields of hippocampus.Methods Wistar rats were exposed to lead from drinking 20,200 and 2 000 μg/ml lead acetate solution respectively for three months,Y maze test was applied to study the effects of lead on learning and memory ability in rats;NADPH diaphorasel(NADPH d) histochemistry and nNOS immunohistochemistry were used to investigate the changes of NOS in different hippocampal subfields.Results Compared with the control,the learning and memory ability of lead exposed rats was significantly decreased ( P < 0.05); the blood and hippocampus lead content was increased in 200 μg/ml and 2 000 μg/ml lead exposed rats;the number of NOS positive neurons in CA1 of 200 μg/ml and 2 000 μg/ml lead exposed rats(51.59±6.30 and 47.27±6.87 respectively) was significantly decreased than control rats(58.92±5.61, P < 0.05), but no significant changes in CA3;the number of nNOS positive neurons in CA1 of 2 000 μg/ml lead exposed rats(49.56± 6.70) was also significantly decreased than control rats( 64.54± 12.46, P < 0.05), but no significant changes in CA3. Conclusion The effects of lead on LTP in hippocampus might be related to the changes of NOS in subfields of hippocampus in lead exposed rats.更多还原