目的　观察急性高原缺氧大鼠交感神经节内交感神经元细胞超微结构及酪氨酸羟化酶（TH）表达的变化，为探讨TH在高原高血压病发生发展中的作用提供依据。  方法　WKY大鼠随机分为平原对照组（C）、缺氧1d组（H1）、缺氧3d组（H3）、缺氧7d组（H7）4组。应用电镜技术，观察低氧环境下交感神经节内交感神经元细胞超微结构的变化；应用qPCR和Western blot法，研究大鼠交感神经节内TH表达的变化。  结果　与同周龄的C组大鼠相比较，缺氧组大鼠血压明显升高（P<0.05）；qPCR和Western blot结果显示：与同周龄的C组大鼠相比，H1组、H3组大鼠交感神经节内TH表达降低，H7组大鼠TH表达增高（P<0.05）；电镜结果显示：高原低氧环境下交感神经细胞的形态、细胞器的数量和结构均有改变。  结论　急性高原低氧对大鼠交感神经节内交感神经元细胞形态结构存在一定影响，并影响TH表达的变化，从而影响高血压的形成。

Objective 　To discuss the effects of tyrosine hydroxylase (TH) in the occurrence and development of high altitude hypertension by observing the changes of the ultramicrostructure of the sympathetic nerve cells and the expression TH in superior cervical ganglion of rats.　Methods　WKY rats were randomly divided to be raised at plain or in the altitude chambers imitating the environment at 5000 m for 1 d, 3 d and 7 d, respectively. Electron microscopy was used to examine the changes of the ultramicrostructure of the sympathetic nerve cells. Real-time PCR and Western blot method were used to examine the mRNA and protein expression of TH.　Results　The blood pressure of hypoxia rats was obviously higher than C group（P<0.05）;the results of Real-time PCR and Western blot showed that mRNA and protein expression of TH in superior cervical ganglion of H1 and H3 groups were lower than C group（P<0.05）, but the expression in H7 group were higher than C group. The results of electron microscopy showed that the morphology of sympathetic nerve cells, quantity and structure of cell organelle were changed in the circumstance of plateau.　Conclusions   TH may participate in the occurrence of high altitude hypertension through certain complex mechanisms.