肝性脑病大鼠海马CA3区神经元形态和一氧化氮合酶表达的变化

目的观察肝性脑病模型组和正常对照组大鼠脑海马CA3区神经元的变化及一氧化氮合酶(NOS)的表达;探讨海马CA3区神经元的形态学改变及一氧化氮(NO)在肝性脑病发病机制中的作用。方法雄性大鼠50只,实验开始前所有动物均进行莫里斯水迷宫测试,之后将动物分为对照组和实验组。9周后建立CCL4肝性脑病模型,分别取两组大鼠海马组织进行尼氏染色及烟酰胺腺嘌呤二核苷酸-黄递酶(NADPH-d),染色。结果尼氏染色发现,实验组大鼠海马神经元数目减少、染色较浅,胞质内尼氏体减少或消失;NADPH-d染色发现,实验组可见粗大轴突着色,树突联系广泛;对照组则少有粗大轴突着色,树突间联系不如实验组广泛。实验组NOS阳性神经元染色较对照组深,为紫蓝或深蓝色(强阳性及阳性),且阳性神经元数目较多;而对照组染色浅淡,呈浅蓝或与背景同色,为弱阳性。结论肝性脑病时海马受到损伤,NO可能介导了神经元的损伤并参与了肝硬化和肝性脑病的发病,血氨升高是肝性脑病(HE)致病因素之一。

Morphological changes and NOS expression of neurons in CA3 hippocampus of rats

Objective To observe morphological changes and the nitric oxide synthase (NOS) expression of neurons in CA3 hippocampus of rats and investigate morphological changes of hippocampal neurons and the role of nitric oxide (NO) in the pathogenesis of hepatic encephalopathy. Methods Fifty male Wistar rats were divided into the control group and experimental group. Before the experiment all the rats were tested by Morris water maze test. After 9 weeks, a CCL4 model of hepatic encephalopathy was established. The hippocampus of each group was taken out for Nissl staining and dyeing of NADPH-d. Results 1.Nissl’s staining: In the experimental group, the number of neurons in hippocampus were less than the control group and dyed lighter, Nissl bodies were also reduced. 2. NADPH-d staining results: In the experimental group, the axon was dyed more deep，widespread dendrites connections were observed. In the control group there were a few positive axons and less connections between dendrites. The color in the experimental group was blue or deep blue and showed positive or strong positive with NADPH-d staining, while in the control group showed weak positive. Conclusion Hepatic encephalopathy can lead to hippocampus injury. NO may mediate the process and the blood ammonia level is one of the pathogenesis of HE.