Function of dietary cyclodextrins on some copper proteins

目的：研究饲粮中添加环糊精（CDs）对大鼠肝脏金属硫蛋白（MT）、铜、锌超氧化物歧化酶（SOD）、铜蓝蛋白和含铜细胞色素C氧化酶mRNA水平的影响。测定MT的蛋白质含量、SOD、铜蓝蛋白和细胞色素C氧化酶活性。方法：体重75或85 g的雄性Wistar生长大鼠分别饲喂基础饲粮、5%α-、5%β-或5%γ-CD，饲喂7 d。测定肝脏中MT、SOD、铜蓝蛋白和细胞色素C氧化酶的mRNA水平。测定肝脏中MT蛋白含量及SOD、铜蓝蛋白、细胞色素C氧化酶活性。同时测定肝脏中铜和锌的含量。结果：用β-CD饲喂大鼠可降低大鼠的进食量，但各组间体重增加无显著差异。饲粮中添加环糊精对每100 g体重肝脏重量无影响。肝铜含量在β-CD喂养的大鼠肝脏中有升高或趋于升高的趋势。β-和γ-CD均显著提高大鼠肝脏MT和Cu、Zn-SOD mRNA水平。饲喂β-或γ-CD均可提高肝脏MT蛋白含量。饲粮α-CD可提高肝脏Cu、Zn-SOD活性。饲粮中β-CD有增加的趋势，饲粮中γ-CD显著提高了肝脏细胞色素C氧化酶mRNA水平。饲料中γ-CD显著提高了肝脏细胞色素C氧化酶活性。饲粮γ-CD显著提高了肝脏铜蓝蛋白mRNA水平。饲喂β-CD使肝铜含量增加。而肝脏锌含量不受膳食cd的影响。饲粮中添加α-、β-或γ- cd可提高肾脏MT mRNA水平。结论：饲粮中β-或γ-CD可诱导部分含铜蛋白mRNA水平升高。由此推测，某些含铜酶的活性可能发生改变。少

Objective : This study was performed to document the effects of dietary cyclodextrins (CDs) on mRNA levels of metallothionein (MT), Cu, Zn-superoxide dismutase (SOD), ceruloplasmin and cytochrome C oxidase containing copper in the liver. Furthermore, the protein content of MT, and the enzyme activity of SOD, ceruloplasmin, and cytochrome C oxidase were estimated.Methodology : Male Wistar growing rats weighing 75 or 85 g were fed the basal, 5%α-, 5%β- or 5%γ-CD diet for 7 days. mRNA levels MT, SOD, ceruloplasmin and cytochrome C oxidase were estimated in the liver. Furthermore protein content of MT and the enzyme activities of SOD, ceruloplasmin, and cytochrome C oxidase in the liver were estimated. Copper and zinc content in the liver were also measured.Results : Feeding rats with β-CD resulted in lower food intake, but the significant difference in body weight gain was not observed among groups. Dietary cyclodextrins had no effect on liver weight per 100 g body weight. Liver copper co … More ntents in the liver of rats fed the β-CD increased or tended to be higher. Hepatic mRNA levels of MT and Cu, Zn-SOD significantly increased in rats fed either β- or γ-CD. The feeding with either β- or γ-CD increased the protein contents of MT in the liver. Dietary α-CD increased the hepatic activity of Cu, Zn-SOD. While, dietary β-CD tended to increase and dietary γ-CD significantly increased hepatic mRNA levels of cytochrome C oxidase. Dietary γ-CD significantly increased hepatic activity of cytochrome C oxidase. Dietary γ-CD significantly increased hepatic mRNA levels of ceruloplasmin. Liver copper was increased by feeding the β-CD. While zinc in the liver was not changed by the dietary CDs. mRNA levels of MT in the kidney increased by feeding dietary α-,β- or γ-CDs.Conclusion : Over all results indicate that dietary β- or γ-CD induces the increase in mRNA levels of some proteins containing copper. Thereafter it is surmised that the activities of some enzymes containing copper might be changed. Less