Endothelial cell-derived nitric oxide mobilization is attenuated in copper-deficient rats.
Endothelial cell-derived nitric oxide mobilization is attenuated in copper-deficient rats.
复制标题
缺铜大鼠中内皮细胞来源的一氧化氮动员减弱。
DOI：
10.1139/h08-091
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
Schuschke,DaleA
中科院分区：
文献类型：
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作者：
Falcone,JeffC;Lominadze,David;Johnson,WThomas;Schuschke,DaleA
内皮依赖的一氧化氮(NO)介导的血管扩张功能减弱是饮食铜缺乏时在管道和阻力血管中一致的发现。尽管这种效应已经确立，但这种机制的证据仍然是间接的。本研究旨在测定血管内皮细胞产生和释放的NO的相对量。使用荧光NO指示剂4-amino-5-methylamino-2′，7′-difluorofluorescein(DAF-FM)，我们现在展示了铜缺乏饮食对阻力小动脉内皮细胞产生NO的影响。在一组实验中，对照组和铜络合肺微血管内皮细胞(ECs)被用来检测NO的产生，并在共聚焦显微镜下观察到荧光。给断奶的SD-Dawley大鼠饲喂铜充足(每克食物含铜6.3微克)或缺铜(每克食物含铜0.3微克)的纯净饲料4周。在第二系列实验中，通过显微外科手术分离大鼠提睾肌的一级小动脉，插管，并用(3[N-吗啉]丙磺酸)生理盐溶液(MOPS-PSS)加压。血管腔内加入DAF-FM(5µm ol·L-1)测定NO释放量。铜络合内皮细胞基础DAF-FM荧光强度显著低于对照组。在10−6mol·L-1乙酰胆碱作用下，螯合内皮细胞和缺铜小动脉管腔内的荧光强度明显减弱。结果提示，铜可抑制血管内皮细胞产生和释放NO。这种抑制可能是先前报道的铜缺乏大鼠血管扩张减弱的原因。
The attenuation of endothelium-dependent nitric oxide (NO) mediated vasodilation is a consistent finding in both conduit and resistance vessels during dietary copper (Cu) deficiency. Although the effect is well established, evidence for the mechanism remains circumstantial. This study was designed to determine the relative amount of NO produced in and released from the vascular endothelium. Using the fluorescent NO indicator, 4-amino-5-methylamino-2′,7′-difluorofluorescein (DAF-FM), we now demonstrate the effect of a Cu-deficient diet on the production of NO from the endothelium of resistance arterioles. In one group of experiments, control and Cu-chelated lung microvascular endothelial cells (ECs) were used to assay NO production and fluorescence was observed by confocal microscopy. Weanling Sprague–Dawley rats were fed purified diets that were either Cu adequate (6.3 micrograms Cu per gram of food) or Cu deficient (0.3 micrograms Cu per gram of food) for 4 weeks. In the second series of experiments, first-order arterioles were microsurgically isolated from the rat cremaster muscle, cannulated, and pressurized with (3[N-morpholino]propanesulfonic acid) physiologic salt solution (MOPS-PSS). DAF-FM (5 µmol·L–1) was added in the lumen of the vessel to measure NO release. Baseline DAF-FM fluorescence was significantly lower in Cu-chelated ECs than in controls. In response to 10−6mol·L–1acetylcholine, fluorescent intensity was significantly less in chelated ECs and in the lumen of Cu-deficient arterioles. The results suggest that production and release of NO by the vascular endothelium is inhibited by a restriction of Cu. This inhibition may account for the attenuated vasodilation previously reported in Cu-deficient rats.