Function of dietary cyclodextrins on some copper proteins

目的：研究环糊精(CDS)对小鼠肝脏金属硫蛋白(MT)、铜锌超氧化物歧化酶(SOD)、铜蓝蛋白和含铜细胞色素C氧化酶基因表达的影响。测定MT蛋白含量、超氧化物歧化酶、铜蓝蛋白和细胞色素C氧化酶活性。方法：雄性Wistar大鼠体重75和85g，分别饲喂基础饲料、5%α-、5%β-和5%γ-Cd，连续7d。测定肝脏MT、SOD、铜蓝蛋白和细胞色素C氧化酶的mRNA水平。测定肝组织中金属硫蛋白含量及超氧化物歧化酶、铜蓝蛋白和细胞色素C氧化酶活性。结果：β-CD可使大鼠摄食量减少，但体重增加差异无统计学意义。饲料中的环糊精对每100g体重的肝脏重量没有影响。肝铜公司…饲喂β-CD的大鼠肝脏中的含量增加或有升高的趋势。饲喂β-或γ-Cd的大鼠肝脏金属硫蛋白和铜、锌-超氧化物歧化酶水平显著升高。饲喂β-CD或γ-CD均能提高肝脏MT的蛋白质含量。饲料中α-Cd可提高肝脏中铜、锌-超氧化物歧化酶的活性。而饲料β-Cd有增加的趋势，且γ-Cd显著增加肝脏细胞色素C氧化酶的表达水平。饲料中添加γ-Cd可显著提高肝脏细胞色素C氧化酶活性。饲料中γ-Cd显著提高了肝脏铜蓝蛋白的表达水平。饲喂β-CD可提高肝脏铜含量。而肝脏中的锌不受膳食镉的影响。饲喂α-，β-或γ-Cd可提高肾脏中MT的基因表达水平。结论：上述结果表明，饲料中添加β-或γ-Cd可诱导某些含铜蛋白质的基因表达水平升高。此后，推测某些含铜的酶的活性可能会发生变化。较少

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