急慢性应激对大鼠中枢神经肽Y腺苷酸环化酶表达的影响

目的 探讨急、慢性应激对大鼠行为及不同脑区神经肽Y、腺苷酸环化酶表达的影响.方法 将30只雄性SD大鼠随机分为急性应激组、慢性应激组和正常对照组,每组10只,用强迫游泳和空瓶刺激分别制作急性和慢性应激模型,采用开野实验箱观察各组大鼠进入中央格次数、停留时间、外周格子数、修饰次数、粪便粒数;采用免疫组织化学方法检测各组大鼠神经肽Y、腺苷酸环化酶在前额叶皮质,海马CA3区,纹状体的表达水平,并进行相关分析.结果 开野实验箱中观察各组大鼠行为学指标显示,三组进入中央格次数、停留时间、外周格子数及修饰次数比较均有显著性差异(F=2.31、2.76、4.20、4.37,P<0.01～0.05).神经肽Y表达水平急、慢性应激组在前额叶皮质、纹状体均显著高于正常对照组(F=7.37、4.60,P<0.01),在海马CA3区慢性应激组表达水平显著高于正常对照组(P<0.05),而急性应激组无显著性变化.腺苷酸环化酶在慢性应激组大鼠的前额叶皮质,海马CA3,纹状体的表达水平显著低于正常对照组(P<0.05),而急性应激组大鼠在纹状体表达有所增加(P<0.05).急性应激组大鼠前额叶皮质,纹状体腺苷酸环化酶的表达和该组大鼠在开野实验箱中的停留时间,修饰次数成显著正相关(r=0.944、0.944、0.868、0.783).结论 强迫游泳和空瓶应激可诱导大鼠情绪障碍,神经肽Y、腺苷酸环化酶与情绪有关,前额叶皮质、纹状体腺苷酸环化酶的表达在急性应激状态的生理改变中有重要作用.

The effects of acute,chronic stress on the expression of cental nerve neuropeptide Y and adenylcyclase in rats

Objective To explore the effects of acute and chronic stress on behavior and expression of neuropeptide Y and adenylcyclase in rats' different encephalic region.Mehtods Thirty male Sprague-Dawley rats were randomly divided into acute stress,chronic stress and control group(each n=10),acute and chronic stress models were made with forced swimming and empty bottle stimulation separately,and frequency of getting into central grille,detention time,outer grille numbers,modifying numbers and dejecture grain number were observed with open-field experimental box;expressions of neuropeptide Y and adenylcyclase in prefrontal lobe cortex,hippocampus CA3,striatum of the groups were observed using the immunohistochemistry method and correlation analyses conducted.Results There were significant differences in frequency of getting into central grille,detention time,outer grille numbers,modifying numbers among the 3 groups(P<0.01~0.05).Expression levels of neuropeptide Y in prefrontal lobe cortex and striatum were markedly higher in both acute and chronic and in hippocampus CA3 in the chronic than in the control group(P<0.01,P<0.05).Expressions of adenylcyclase in prefrontal lobe cortex,hippocampus CA3 and striatum were significantly lower in the chronic than in the control group(P<0.05)and those in striatum in the acute group increased(P<0.05).Expressions of adenylcyclase in prefrontal lobe cortex and striatum were significantly positively related to detention time and modifying numbers in the acute group.Conclusion Forced swimming and empty bottle stimulation could induce rats' emotional disorder,neuropeptide and adenylcyclase are related to emotion and expressions of adenylcyclase in prefrontal lobe cortex and striatum has an important role in physio-changes in acute stress state.