人嗜酸性粒细胞NADPH氧化酶的定位及gliotoxin的抑制作用

The Localization of NADPH Oxidase in Human Eosinophils and the Inhibitory Effect of Gliotoxin on It

目的研究NADPH氧化酶在人体嗜酸性粒细胞中的细胞化学定位及gliotoxin对其活性的抑制作用。方法用蛋白激酶C的激活剂佛波豆蔻乙酯(phorbol myristate aceta,PMA)和gliotoxin对嗜酸性粒细胞预处理,然后用Ce3+为捕捉剂检测活性氧,作为电镜下NADPH氧化酶活化的标志。结果PMA组:在嗜酸性粒细胞内囊泡呈放射状排列,大小形态各异的囊泡腔面有很多显示NADPH氧化酶活性的致密颗粒存在。PMA+gliotoxin组:嗜酸性和中性粒细胞内显示该酶活性的颗粒都明显减少,但后者减少程度明显。结论嗜酸性粒细胞经刺激后,位于细胞内囊泡膜的腔面的NADPH氧化酶被激活,其活性强于中性粒细胞。gliotoxin对嗜酸性粒细胞产生过量.O2-有明显的抑制作用。

Objective To study the cytochemical localization of NADPH oxidase in eosinophil and the inhibitory effect of gliotoxin on its activity. Methods The human eosinophils were pretreated in the media with phorbol 12-myristate 13-aeetate（PMA） or with PMA plus gliotoxin. The reactive oxygen species, wieh were the activity products of NADPH oxidam,were measured eytoehemicaUy by electron microscopy by using Ce^＋3 as capture. Results In the PMA-treated group, many endosomes of different shapes and sizes were observed in the eosinophils. A lot of dense particles denoting the NADPH oxidase activity were attached to luminesee face of the vesicle membrane. However, in the group there were rarely dense particles spreading in the cytoplasm. In the PMA＋ gliotoxin group, the dense particles decreased prominently both in eosinophils and in neutrophils, but the decrease was more in the latter. Conclusion NADPH oxidase located on the laeunal face of endosome membrane in eosinophils is easily being activated after stimilation and is beneficial to host defense mechanism against phagocytic organism. Its activity in eosinophils is greater than that in neutrophils. Gliotoxin has an inhibitory effect on · O2^- overproduction of NADPH oxidase.