血管紧张素-Ⅱ对急性缺氧时血管内皮细胞分泌内皮素的影响及金钠多的保护作用研究

A Study on the Effects of Angiotensin-Ⅱ on VEC Secreting ET Induced by Hypoxia and the Protection of Ginaton

目的观察急性缺氧条件下,血管紧张素-Ⅱ对血管内皮细胞分泌内皮素的影响及金钠多的保护作用。方法将培养的血管内皮细胞分为7个组:对照组、单纯缺氧组、单纯血管紧张素-Ⅱ组、缺氧加血管紧张素-Ⅱ组、缺氧加血管紧张素-Ⅱ加高浓度金钠多组、缺氧加血管紧张素-Ⅱ加中浓度金钠多组和缺氧加血管紧张素-Ⅱ加低浓度金钠多组。除对照组和单纯血管紧张素-Ⅱ组外,其他各组置于低压舱内上升至5000m高度、停留30min,对培养的各组血管内皮细胞进行缺氧。用放射免疫法测定缺氧及血管紧张素-Ⅱ和金钠多作用前、作用后0·5h、6·0h、24·0h各组细胞培养液中的内皮素含量。结果(1)急性缺氧和单纯血管紧张素-Ⅱ均可明显促进血管内皮细胞分泌内皮素(P<0·01),在急性缺氧和血管紧张素-Ⅱ双重因素作用下促血管内皮细胞分泌内皮素的作用高于单纯缺氧组和单纯血管紧张素-Ⅱ组(P<0·01)。(2)金钠多能显著降低缺氧加血管紧张素-Ⅱ促血管内皮细胞分泌内皮素的作用,在缺氧加血管紧张素-Ⅱ作用后0·5h,高浓度金钠多的保护作用要优于中、低浓度金钠多,而在缺氧加血管紧张素-Ⅱ作用后6·0h和24·0h,则中浓度和低浓度金钠多的作用要优于高浓度组。结论在急性缺氧条件下,血管紧张素-Ⅱ可显著增加培养的血管内皮细胞分泌内皮素的功能,金钠多能显著抑制缺氧条件下血管紧张素-Ⅱ促血管内皮细胞分泌内皮素的作用,且中、低浓度的金钠多的保护作用要明显强于高浓度金钠多。

Objective To explore the effects of Angiotesin - 2 （ Ang -Ⅱ ） on vascular endothelial cells （ VEC ） secreting endothelia （ET） induced by hypoxia and the protection of different concentration Ginaton. Methods Cultured VEC were divided into 7 groups ： ①control group; ②simple hypoxia group; ③simple Ang - Ⅱ group; ④ hypoxia ＋ Ang - Ⅱ group; ⑤hypoxia ＋ Ang -Ⅱ ＋ high concentration Ginaton group; ⑥hypoxia ＋ Ang - Ⅱ ＋ middle concentration Ginaton group; ⑦ hypoxia ＋ Ang - Ⅱ ＋ low concentration Ginaton group. All groups except the control group and the simple Ang- Ⅱ group were underwent hypoxia which was produced by hypobaric chamber （5 000 m, 30 min）. The ET content in supernatant of VEC before hypoxia and 0. 5 h after hypoxia, 6. 0 h after hypoxia as well as 24. 0 h after hypoxia were measured with radioimmunoassay. Resuits （ 1 ） Simple hypoxia or simple Ang - Ⅱ promoted the VEC secreting ET significantly （ P 〈 0. 01 ） ： （ 2 ） Ang - Ⅱ increased ET release of VEC induced by hypoxia, the effect was significant compared with simple hypoxia （ P 〈0. 01 ） ; （3） Ginaton had the effect to inhibit the VEC secreting ET induced by hypoxia combined Ang - Ⅱ （ P 〈0. 01 ）. At the time of 0. 5h after hypoxia combined Ang - Ⅱ , the protective effect of high concentration Ginaton was more obvious compared with middle and low concentration Ginaton. At the time of 6. 0 h and 24. 0 h after hypoxia combined Ang - Ⅱ the protective effects of middle and low concentration Ginaton were more significant than that of the high concentration Ginaton. Conclusion Ang - Ⅱ can significantly increase the ET release of VEC induced by hypoxia. Ginaton has the effect to decrease the VEC secreting ET induced by hypoxia combined Ang - Ⅱ , and the protection of Ginaton with middle and low concentration is obviously higher than Ginaton with high concentration.