糖水餵食與限食對大鼠抗氧化狀況的影響

The Effects of Sucrose Water and Food Restriction on Antioxidative Status in Rats

許多研究顯示食用蔗糖會誘發氧化壓力，本實驗目的在於探討糖水餵食與限食對大鼠抗氧化狀況的影響。Wistar品系雄鼠分成控制組(C)、糖水組(30% sucrose waters)與對飼育組(SP)，飼養7週後取血液與肝臟，分析脂質過氧化指標TBARS、抗氧化分子與酵素活性。結果顯示糖水組顯著降低飼料攝取量，總熱量攝取及終體重與控制組相當，腹壁後脂肪量顯著高於控制組；SP組飼料攝取量為控制組的55%，似限食效應，終體重顯著最低。糖水鼠顯著誘發血清三酸甘油酯(TG)升高，分別為C組與SP組的1.64倍、2.2倍，此為糖水獨特效應。抗氧化系統方面，血清α-生育醇含量與α-生育醇／TG比率均因糖水餵食而顯著下降，血清GSH含量與紅血球抗氧化酵素活性三組之間無統計差異。肝臟結果顯示餵食糖水顯著降低α-生育醇濃度，SP組之TBARS顯著低於控制組，catalase活性與蛋白質量均顯著升高，此為限食獨特效應。結論：糖水餵食顯著增加大鼠血清TG含量與腹壁後白色脂肪，此效應與糖水促進脂質生合成有關，顯著惡化維生素E營養狀況，但不影響紅血球與肝臟抗氧化酵素表現；限食顯著降低大鼠體重、肝臟TBARS，增加catalase表現量，糖水餵食對血脂質的代謝有較顯著的影響，而限食對抗氧化防禦系統表現則有特殊效應存在。

Several studies have shown that consumption of sucrose facilitates oxidative damage but the mechanisms involved are unclear. The aim of this study was to investigate effects of sucrose water and food restriction on antioxidative status in rats. Male Wistar rats were divided into three groups, a control group (C), 30% sucrose water-fed groups (S) and PF group that was pair-fed to the S group with the C diet. The TBARS content, antioxidative moleculars and associated enzymes were measured in blood and liver after 7-wks feeding. Our results showed the total food intake was decreased significantly in S group compared with C group (p＜0.05). In S group, the weight of retroperitoneal fat and serum TG (triglyceride) content were higher significantly than the other 2 groups, but a lower α-tocopherol content in serum and liver were observed. The activities of antioxidant enzymes in RBC were not different between 3 groups. The serum TG-raising effect was accompanied by significantly lowered α-tocopherol content suggesting that vitamin E depletion may facilitates oxidative damage in sucrose-fed rats. No statistical differences were observed for serum and liver GSH level between 3 groups. However, the TBARS content was decreased significantly and increased the activity and protein abundance of catalase (p＜0.05) by food restriction treatment (SP group). In conclusion, our results showed that high sucrose water had a detrimental effect on vitamin E status, but with specific effects on lipid metabolism. The catalase-raising and TBARS-lowering effect in SP group were observed, suggesting that food restriction may induce a protective defense against oxidative damage.