【摘要】 目前已知下丘脑是应激反应的关键性调节中枢，下丘脑内一氧化氮是否参与应激反应尚未见报道。本文运用ＮＡＤＰＨ－ｄ酶组化技术和计算机图象分析方法，对束缚应激大鼠下丘脑室旁核（ＰＶＮ）和视上核（ＳＯＮ）一氧化氮合酶（ＮＯＳ）阳性神经元的相对切面面积和平均灰度进行了分析。结果显示，大鼠在急性束缚应激４小时后，其下丘脑ＰＶＮ和ＳＯＮ内的ＮＯＳ阳性神经元的平均灰度值与正常大鼠比较均明显降低（Ｐ＜０．００１）；ＳＯＮ的ＮＯＳ阳性神经元的相对切面面积明显大于正常大鼠（Ｐ＜０．００１），但ＰＶＮ的ＮＯＳ阳性神经元的相对切面面积未见明显改变（Ｐ＞０．０５）。以上结果说明束缚应激使大鼠下丘脑ＰＶＮ和ＳＯＮ的ＮＯＳ活性增强更多还原

【Abstract】 It is well established that the hypothalamus is the pivotal mediated center of stress response. But whether nitric oxide within hypothalamus is involved in this response or not still remains to be unclear, Using NADPH diaphorase histochemistry technique and microcomputerized image analysis, we observed the changes of the gray degree and the sectional area of nitric oxide synthase (NOS) positive neurons in the hypothalamic paraventricuar nucleus ( P VN) and the supraoptic nucleus (SON) after immobilization stress. Results showed that after rats had been exposed to 4 hours immobilization stress, the grey degree of NOS positive neurons in PVN and SON became significantly lower than that of normal rats ( P <0 001).The sectional area of NOS positive neurons in SON became larger than that of normal rats ( P <0 001). But there was no remarkable found in PVN. The above results demonstrated that NOS enzyme activity in PVN and SON was increased after immobilization stress.更多还原