不同果糖比例飼料誘發大鼠代謝症候群現象之探討

Inducing Metabolic Syndrome in Rats with Diet Containing Different Percentages of Fructose

顏肇均(Chao-Jium Yen)

指導教授 ： 吳亮宜

中原大學/理學院/化學研究所/碩士(2009年)

https://doi.org/10.6840/cycu200900130

摘要

代謝症候群是由多種與心血管疾病相關的危險因子所組成。研究指出，有代謝症候群的徵狀，得到糖尿病、心臟病的機率會大幅的增加。依據前人的研究，大鼠長期餵飼高果糖飼料，可以誘發出高血糖、高三酸甘油酯血症和高血壓等類似代謝症候群症狀。此模式的飼料中60%為碳水化合物，且碳水化合物全部都是以果糖為主，若保健食材含有碳水化合物，則無法適用此模式。因此本篇研究，將碳水化合物部份所含之果糖比例降低，來評估大鼠代謝症候群誘發之情形。
實驗將Sprague-Dawley雄性大鼠分四組，分別以40% (F40)、50% (F50)、60% (F60)高果糖飼料和一般飼料(Control, C)餵飼13週。期間每週觀察體重和血壓變化，每兩週採集禁食血液，測量血漿葡萄糖、胰島素、三酸甘油酯的變化，每四週進行一次口服葡萄糖耐受性試驗，實驗結束，將動物犧牲，採集血液，分析生化指標並取肝臟測量肝中三酸甘油酯、膽固醇。同時分析脂肪組織中胰島素訊息傳遞相關蛋白質含量。
結果顯示在F40組的大鼠，自第三週起收縮壓、三酸甘油酯都有顯著的增加。從第八週後的口服葡萄糖耐受性試驗上觀察到有胰島素阻抗的發生。餵食十三週後其禁食血漿葡萄糖、胰島素、三酸甘油酯、膽固醇及TBARS均顯著高於C組，顯示出以40%果糖餵飼後，可誘發出代謝症候群等諸多症狀。另外，實驗中亦發現F40大鼠脂肪組織上胰島素訊息傳遞相關之胰島素接受器受質-1和葡萄糖轉運蛋白4顯著低於C組，代表長期餵飼40%果糖，亦引誘其胰島素訊息傳遞異常。
而F50及F60大鼠中，我們亦觀察到與F40組同樣的現象發生，唯F60組胰島素阻抗之情形在第四週即可發現。
總結，大鼠以40%以上果糖飼養十三週後可誘導出高血糖症、高血壓、高胰島素血症及高三酸甘油酯血症等諸多類似代謝症候群等症狀。

關鍵字

代謝症候群 ； 高果糖動物模式 ； 胰島素阻抗

並列摘要

Metabolic syndrome is composed of high risk factors associated with cardiovascular disease. The patients, those who have metabolic syndrome, will have higher risk to suffer from the diabetes mellitus (DM) and coronary vascular disease (CVD). In the past studies, the metabolic syndrome can be induced in the rats fed with high fructose diet for long term. However, the model is based on the 60% carbonhydrate and all the carbonhydrates are fructose. If the healthy food contains carbohydrate, then it is not suitable for this model. Therefore the purpose of this study is to investigate of metabolic syndrome in rats fed with adjustment of carbohydrates which consisted of 40%, 50%, 60% fructose.
Experiments were performed in male Sprague-Dawley rats that divided in four group: in control group (C), rats were maintained on standard chow and, in F40, F50, F60 group, rats were fed a 40%, 50%, 60% high-fructose diet respectively during 13 weeks. Body weight and blood pressure were measured per week. Fasting blood was collected biweekly, and plasma glucose, insulin, triglyceride were examined. The oral glucose tolerance test were performed per month. At the end of the experiment, rats were killed by decapitation. Plasma was collected for further bioassay. The liver triglyceride, cholesterol were assayed as well. Meanwhile, the contents of insulin signaling pathway related proteins in adipossue tissue were determined.
The data shown that, 40% fructose feeding for 3 weeks cause significantly increase in systolic blood pressure and plasma triglyceride. And insulin resistance was demonstrated after the 8th week by OGTT. At the end of the experiment. Plasma glucose, insulin, triglyceide, cholesterol and TBARS of F40 group were significantly higher than group C. These results indicated that 40% fructose diet could induced a cluster of disorders in metabolic syndrome. Further, the 40% fructose diet feeding rats showed decreased expressions of insulin signaling pathway related proteins, including insulin receptor substrates-1 and glucose transporter 4.The phenomena happened in group F40 were also shown in group F50 and F60. The only difference is that the insulin resistance occurred in the 4th week in group F60.
In summary, the rats fed with over 40% fructose diet for 13 weeks will be induced metabolic disorders, including hyperglycaemia, hypertension, hyperinsulinemia and hyperlipidemia.

並列關鍵字

metabolic syndrome ； high fructose animal model ； insulin resistance

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