用ＮＡＤＰＨ－ｄｉａｐｈｏｒａｓｅ组织化学和免疫细胞化学方法，观察和比较了一氧化氮合酶、酪氨酸羟化酶、５－羟色胺、Ｐ物质和亮氨酸脑啡肽在自发性高血压大鼠和正常对照大鼠孤束核的分布。结果显示，孤束核内一氧化氮合酶阳性细胞在高血压组少于对照组，有显著性差异（Ｐ＜０．０５）。孤束核Ｐ物质和亮氨酸脑啡肽免疫阳性物在高血压组多于对照组；酪氨酸羟化酶免疫阳性物高血压组少于对照组；５－羟色胺免疫阳性物在两组的分布无明显差异。提示一氧化氮在孤束核是一种降压性局部神经调质，与其在心血管系统的降压作用一致。中枢Ｐ物质含量的异常增加可能是高血压发病的原因之一。孤束核脑啡肽含量的异常增加与高血压的形成有关，痛觉和高血压之间可能存在一些共同的发生机制。酪氨酸羟化酶在高血压组降低提示孤束核内酪氨酸羟化酶对维持正常血压发挥重要作用．孤束核内５－羟色胺与血压调节无关。 NADPH-diaphorase histochemical and immunocytochemical methods were used to observe and compare nitric oxide synthase, tyrosine hydroxylase, serotonin, substance P and leucine enkephalin in spontaneously hypertensive rats and Distribution of solitary nucleus in normal control rats. The results showed that the nucleus of nucleus tractus solitarius in the hypertensive group less than the control group, there was a significant difference (P <0.05). Solitary nucleus P substance and Leu-enkephalin-immunopositive were more in the hypertension group than in the control group; tyrosine hydroxylase-immunopositive hypertension group was less than the control group; Serotonin-immunopositive group was in two groups No significant difference in the distribution. Suggesting that nitric oxide is a hypotensive local neuromodulator in the nucleus tractus solitarius, consistent with its hypotensive effects in the cardiovascular system. Central P substance content of the abnormal increase may be one of the causes of hypertension. The abnormal increase of enkephalin concentration in the nucleus of solitary tract is related to the formation of hypertension. There may be some common mechanisms of the occurrence of pain and hypertension. The decrease of tyrosine hydroxylase in the hypertensive group suggests that tyrosine hydroxylase in the nucleus tractus solitarius plays an important role in maintaining normal blood pressure. Nucleus tractus solitarius has nothing to do with blood pressure regulation.