Supplementary Material for: Effects of Selenium in the Microcirculation of Fructose-Fed Hamsters

<b><i>Background and Aims:</i></b> Fructose intake is directly related to vascular dysfunction and it is a risk factor for the development of metabolic and cardiovascular diseases, such as obesity, diabetes, and hypertension. Selenium, a component of antioxidant enzymes, improves hyperglycemia and vascular function in diabetic animals. The aim of this study was to evaluate the effects of dietary selenium supplementation on microcirculatory and metabolic parameters of fructose-fed hamsters. <b><i>Methods and Results:</i></b> Male hamsters (<i>Mesocricetus auratus</i>) had their drinking water substituted or not by 10% fructose solution for 60 days, during which their microcirculatory function was evaluated in the cheek pouch preparation. Blood glucose and serum insulin levels were also tested. Microcirculatory responses to acetylcholine (an endothelium-dependent vasodilator) and to sodium nitroprusside (SNP, an endothelium-independent vasodilator), and macromolecular permeability increase induced by a 30-min ischemia/reperfusion (I/R) procedure, showed that endothelium-dependent and independent vasodilatation was significantly increased in animals that had high selenium supplementation, in both the control and fructose-fed groups. Selenium supplementation protected against plasma leakage induced by I/R in all control and fructose-fed groups. <b><i>Conclusion:</i></b> Our results indicate that dietary selenium supplementation reduces microvascular dysfunction by increasing endothelial-dependent and independent dilatation and reducing macromolecular permeability increase in fructose-fed animals.

<b><i>背景与研究目的：</i></b> 果糖摄入与血管功能障碍（vascular dysfunction）直接相关，且是肥胖、糖尿病、高血压等代谢与心血管疾病（metabolic and cardiovascular diseases）发生的危险因素。硒（Selenium）作为抗氧化酶（antioxidant enzymes）的组成成分，可改善糖尿病模型动物（diabetic animals）的高血糖症（hyperglycemia）与血管功能。本研究旨在评估膳食补硒对果糖喂养仓鼠的微循环与代谢参数（metabolic parameters）的影响。<b><i>方法与结果：</i></b> 选取雄性金黄仓鼠（Mesocricetus auratus），随机分为两组：一组以10%果糖溶液替代饮用水喂养，另一组给予常规饮用水，持续60天。期间采用颊囊微循环模型（cheek pouch preparation）评估其微循环功能，并检测血糖（blood glucose）与血清胰岛素（serum insulin）水平。针对乙酰胆碱（acetylcholine，内皮依赖性血管舒张剂（endothelium-dependent vasodilator））与硝普钠（sodium nitroprusside，SNP，内皮非依赖性血管舒张剂（endothelium-independent vasodilator））的微循环反应，以及30分钟缺血再灌注（ischemia/reperfusion，I/R）操作诱导的大分子通透性（macromolecular permeability）升高情况的检测结果显示：无论对照组还是果糖喂养组，高剂量补硒动物的内皮依赖性与非依赖性血管舒张功能均显著提升；在所有对照组与果糖喂养组中，补硒均可对抗I/R诱导的血浆外渗（plasma leakage）。<b><i>结论：</i></b> 本研究结果表明，膳食补硒可通过增强内皮依赖性与非依赖性血管舒张功能，降低果糖喂养动物的大分子通透性升高，从而改善微血管功能障碍（microvascular dysfunction）。