不同周龄自发性高血压大鼠血管内皮功能及氧化应激的变化研究

目的: 观察不同周龄的自发性高血压大鼠(SHR)内皮功能变化、体内的氧化应激状态及其对血管内皮功能的影响。方法: 将SHR随机分为3组:5周、16周及40周龄组,每组各15只。观察SHR离体胸主动脉和肾动脉对乙酰胆碱(Ach)的反应性,并对其内皮功能变化进行比较,分别使用放射免疫法、硝酸还原酶法、硫代巴比妥酸比色法和5,5'-二硫代双(2-硝基苯甲酸)(DTNB)法检测血中内皮素(ET)、一氧化氮(NO)、丙二醛(MDA)和谷胱甘肽过氧化物酶(GSH-Px)含量。结果: 内皮依赖性血管舒张功能随着周龄的增加而减弱。随着周龄的增加,血管活性物质NO/ET及氧化应激标志GSH-Px、MDA发生变化。16周及40周血清NO低于5周龄SHR ;16周及40周ET分泌水平无明显差别,与5周相比无显著差别;40周MDA含量 与5周 和16周 相比明显增加(P<0.01);而40周GSH-Px活力 与5周 和16周 相比明显降低(P<0.01)。结论: SHR存在内皮功能损伤及氧化应激的增加,随着周龄的增加损伤加重。

Endothelium function and oxidation stress in spontaneous hypertensive rats of different weeks of age

AIM: To observe the endothelial function and oxidation stress in spontaneous hypertensive rats (SHR) of different weeks of age.METHODS: Endothelium-dependent vasodilation of exsomatized aorta thoracalis and renal artery in 5 week-, 16 week- and 40 week-old SHR was observed and compared. Radioimmunoassay and the methods of nitrate reductase, thiobarbituric acid and 5,5'-dithiobis(2-nitrobenzoic acid) were used to measure the levels of endothelin (ET), nitric oxide(NO),malondialdehyde(MDA) and glutathione peroxidase(GSH-Px),respectively.RESULTS: The results indicated that the endothelium-dependent vasodilation was weakened along with aging. Vasoactive substance such as NO/ET and the oxidized stress symbolized by GSH-Px or MDA were also changed along with aging. The level of serum NO in 16 and 40 week-old SHR were lower than that in 5 week-old SHR ( P<0.01). No significant difference of the ET level among the 3 groups was observed. The level of MDA in 40 week-old animals was significantly higher than that in 5 week-old SHR and 16 week-old SHR (P<0.01). The activity of GSH-Px in 40 week-old SHR was significantly lower than that in 5 week-old SHR and 16 week-old SHR (P<0.01).CONCLUSION: The damaged endothelial function and increased oxidation stress are existed in SHR and are aggratated with aging.