目的　观察高脂血症大鼠海马中神经元型一氧化氮合酶 (nNOS)及神经营养因子 3(NT 3)的变化 ,并探讨其临床意义。方法　采用HE和SABC免疫组织化学染色方法 ,结合计算机图像分析系统 ,比较两组海马各区平均光密度(MOD)值。结果　与对照组相比 ,实验组血清总胆固醇(6 6 5mmol/L)及血清低密度脂蛋白胆固醇 (4 4 1mmol/L)升高明显 ,差异有显著性。实验组海马各区nNOS免疫阳性神经元MOD升高 ,尤以CA3区明显 ;NT 3免疫阳性神经元MOD降低 ,以CA1区最为显著。结论　高脂血症大鼠海马中nNOS表达增强而NT 3表达减弱 ,表明高脂血症可导致海马神经元功能改变。 Objective To observe the changes of neuronal nitric oxide synthase (nNOS) and neurotrophic factor 3 (NT 3) in the hippocampus of hyperlipidemic rats and to explore its clinical significance. Methods HE and SABC immunohistochemical staining methods, combined with computer image analysis system, the average optical density (MOD) values ​​of the two groups were compared. Results Compared with the control group, the levels of serum total cholesterol (6 6 5 mmol / L) and serum low density lipoprotein cholesterol (4 4 1 mmol / L) in the experimental group increased significantly. The nNOS immunoreactive neurons in the hippocampus were increased in the experimental group, especially in the CA3 region, while the NT3 immunoreactive neurons were decreased to the most prominent in the CA1 region. Conclusions The expression of nNOS in the hippocampus is increased and the expression of NT 3 is decreased in the hyperlipidemic rats, indicating that hyperlipidemia may lead to functional changes in the hippocampal neurons.