高原不同海拔大鼠垂体ACTH细胞超微结构研究

STUDY ON THE ULTRASTRUCTURE OF PITUITARY ACTH CELLS AT DIFFERENT ALTITUDE IN RATS

目的观察急进高原不同海拔地区大鼠垂体远侧部促肾上腺皮质激素(ACTH)细胞的超微结构变化。探讨ACTH在机体对低氧应激反应中的作用,以及低氧对大鼠ACTH细胞分泌功能的影响。方法本实验将Wistar大鼠随机分为1700m、3100m、4050m三组,分别运至高原相应海拔地区12天后,取大鼠腺垂体用透射电镜方法进行染色,观察高原低氧环境下ACTH细胞的变化。结果结果显示电镜下三组大鼠ACTH细胞的细胞形态、分泌颗粒及线粒体、粗面内质网等细胞器随海拔不同有一定变化。其中3100m和4050m级组ACTH细胞分泌颗粒较对照组(1700m)明显变大变多,且粗面内质网、线粒体等细胞器有所增加,核仁和胞浆也有相应变化。结论高原低氧对大鼠垂体ACTH细胞的超微结构有影响,海拔不同(亦即低氧程度不同时),垂体ACTH内分泌细胞的超微结构有一定的变化规律,提示ACTH可能是参与高原低氧应激反应的重要生理和病理体液因子,其在短期高原低氧应激反应中具有重要的调节作用。

Objective To observe the changes of ultrastructure of ACTH cells in rat＇s pituitary after rats moved to different altitude,and to investigate the role of ACTH in the hypoxic stress and the relationship between hypoxia and the endocrine function of ACTH cells in rat＇s pituitary. Methods Divided Wistar rats into three groups （ 1700m, 3100m, 4050m） , and after moved them to high altitude areas 12 days, observed the changes of ultrastructure of ratg pituitary by using electron microscopy. Results The amount and scale of secretive granules and cellular apparatus of ACTH cells in rats showed some changes between different groups. The 3100m group and 4050m groups have secretive granules and cellular apparatus such as mitochondria and tough endoplasmic reticulum of ACTH cells that bigger and more than the 1700m groupg ,corresponding changes have been found in the nucleolus. Conclusion Hypoxia have some effects on the ultrastructure of ACTH cells in rat＇s pituitary, It showed that ACTH perhaps is a key physiologic and pathophysiologic factor for involving the stress reaction to hypoxia in high altitude.