摘要
目的研究高游离脂肪酸(HFFA)血症致血管内皮细胞功能紊乱是否与全身氧化应激增强以及血管局部烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶p47-phox亚基表达增强有关。方法正常6周龄雄性SD大鼠分为对照组(NC组,静脉输注生理盐水),HFFA组(输注脂肪乳及肝素),以及还原型谷胱甘肽(GSH)干预组(HFFA+GSH组,同时输注脂肪乳、肝素及GSH)。输液前后测血浆FFA水平及GSH/GSSG比值。输液后行超声多普勒检测股动脉内皮依赖性血管舒张功能(EDV)与非内皮依赖性血管舒张(NEDV)功能,实时荧光定量RT-PCR检测胸主动脉NADPH氧化酶p-47phox的mRNA水平,Western blot检测内皮细胞及平滑肌细胞p-47phox蛋白的表达。结果与NC组相比,HFFA组血浆FFA水平明显增高(P<0.05),GSH/GSSG比值下降(P<0.05),EDV明显降低(P<0.01);HF-FA+GSH组血浆GSH/GSSG比值介于HFFA组与NC组之间,EDV较HFFA组明显改善(P<0.05);NADPH氧化酶p-47phox mRNA及蛋白水平HFFA组较NC组明显增加,该增加趋势在HFFA+GSH组中受到明显抑制;p-47phox mRNA和蛋白水平与血浆GSH/GSSG比值呈正相关关系。结论外源性升高血浆FFA水平能诱导机体氧化应激,促进血管局部NADPH氧化酶P-47phox亚基基因的转录与翻译,加重血管局部氧化应激损伤。阻断HFFA血症导致的氧化应激能抑制主动脉NADPH氧化酶表达,部分恢复EDV,提示HFFA血症致血管内皮细胞功能受损与全身及血管局部氧化应激增强有关。
Objective To examine the effects of high FFAs on vascular reactivity and on the transcription and translation of NADPH oxidase p47-phox subunit＇s gene in SD rat aorta to test the hypothesis that high FFA（HFFA）-induced endothelial dysfunction is related with NADPH oxidase subunit over expression. Methods SD rats underwent 18-hr infusions treatment in three group： controls （C, n= 16） received saline, HFFA （n= 16） received intralipid 1.8μl/min and heparin 0. 72U/min; HFFA＋ GSH （n=16） received intralipid ＋heparin ＋ GSH （1.2mg · kg ^-1 · min^-1）. Endothelium-dependent and non-dependent vasodilation, serum FFAs level and GSH/GSSG ratio were evaluated. Thoracic aortas were harvested at the end of infusion and the transcription and translation of NADPH oxidase p47-phox subunit gene in vascular tissure were examined by real-time PCR and western blot. Results Serum FFAs level was remarkably increased （1 567 ± 273μmol/L vs 327.5 ± 50. 7μmol/L, P〈0. 05） and GSH/ GSSG ratio was decreased （41.3±89 vs 82.7±33, P〈0. 05） in HFFA group, which were moderately returned in HFFA ＋GSH group （62.1± 2.3）. Addition of acetylcholine produced a dose-dependent relaxation in aortic rings of C group but it was impaired in HFFA group, which was partly improved in HFFA＋GSH group. Vasodilator response to sodium nitroprusside was identical. NADPH oxidase p47- phox subunit gene transcription and translation in aorta were enhanced in HFFA group but were decreased by GSH. Conclusions HFFA-induced NADPH oxidase subunit p47-phox subunit gene over expression and oxidative stress could be involved in the endothelial dysfunction, and this could be protected by GSH.
出处
《中国糖尿病杂志》
CAS
CSCD
北大核心
2009年第7期493-497,共5页
Chinese Journal of Diabetes
基金
国家自然科学基金资助项目(编号30370679
30570874)
