中文摘要：

目的克隆补硒糖尿病大鼠三磷酸腺苷（ATP）结合盒（ABC）转运蛋白A亚族的成员之一-ABCa5基因片段并检测其在肝脏中的表达水平。方法将前期分离到与补硒有关的糖尿病大鼠差异显示的基因片段（简称差显片段）进行克隆、测序和同源性分析，并对ABCa5基因片段重新设计特异性引物，进行半定量逆转录聚合酶链式反应（RT—PCR）检测，观察其在各组大鼠肝脏组织中表达的变化。结果发现差显片段Se-12的碱基序列与ABCa5基因的同源性为99％。RT—PCR结果表明，与正常对照组（NC）（0．5729±0．0241）相比，糖尿病对照组（DM）（0．1606±0．0075）和糖尿病补硒组（DM＋Se）（0．3857±0．0194）中ABCa5基因mRNA的表达水平明显降低，但DM＋Se组中的该mRNA表达水平较DM组有所升高，差异均有统计学意义（P〈0．05）。结论ABCa5在糖尿病的发病及代谢过程中起着一定的调节作用；补硒可以上调糖尿病大鼠肝脏中ABCa5mRNA的表达水平，这可能是硒改善糖尿病糖、脂代谢紊乱的分子机制之一。

英文摘要：

Objective To clone ABCa5（a member of ATP binding cassette transporters＇A subfamily） gene fragments in diabetic rats supplemented with selenium and detect their expression levels in the rats＇livers. Methods The cDNA fragments isolated from the diabetic rats supplemented with selenium（Se） were cloned, sequenced and homologiously analyzed in order to observe the expression in livers of different groups, The RT - PCR of ABCa5 gene was made by using the primers designed. Results The indentity between Se - 12 different cDNA fragment and ABCa5 gene was 99 %. The result of RT - PCR showed that compared with normal control group （0. 572 9 ＋- 0. 024 1）, the expression levels of ABCa5 mRNA significantly decreased in diabetes mellitus（DM ） （0.160 6 ＋- 0. 0075 ） and DM ＋ Se groups（ 0. 385 7 ＋- 0.019 4） （ P 〈 0.05 ）, the expression levels of ABCa5 mRNA in DM - Se group were higher than those of DM group, and all the differences had statistical significance （P 〈 0.05）. Conclusion ABCa5 can regulate the occurrence and metabolism process of diabetes mellitus in some ways. Selenium supplementation could increase the expression level of ABCa5 mRNA in the livers of diabetic rats. It may be one of the mechanisms that selenium can improve the disorders of glucose and lipid metatolism in diabetic rats.