α-Tocopherol Status and Expression of α-Tocopherol Transfer Protein in Type 2 Diabetic Goto-Kakizaki Rats
α-Tocopherol Status and Expression of α-Tocopherol Transfer Protein in Type 2 Diabetic Goto-Kakizaki Rats
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DOI：
10.3177/jnsv.59.64
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发表时间：
2013-02-01
影响因子：
1.6
通讯作者：
Tamai, Hiroshi
中科院分区：
文献类型：
--
作者：
Miyazaki, Hiroshi;Takitani, Kimitaka;Tamai, Hiroshi
维生素E是一种重要的脂溶性维生素抗氧化剂，在细胞膜上表达，防止脂质过氧化的传播。α -生育酚转移蛋白（α - ttp）是一种位于肝细胞内的细胞质蛋白，是循环α -生育酚水平的主要调节剂。2型糖尿病是一种代谢紊乱，以高血糖为特征，由胰岛素抵抗引起。脂质过氧化促进2型糖尿病的临床进展和并发症的发生。关于糖尿病患者体内维生素E状况的动物和人体实验结果相互矛盾。本研究旨在研究2型糖尿病模型Goto-Kakizaki （GK）大鼠体内维生素E的含量和α - ttp的表达。与对照组相比，糖尿病GK大鼠血浆和肝脏中α -生育酚水平升高。与对照组相比，GK大鼠肝脏中cuzn -超氧化物歧化酶（SOD）和Mn-SOD基因表达无明显变化。与对照组相比，GK大鼠肝脏α - ttp基因表达增加。提示肝脏α - ttp基因表达水平升高可能影响糖尿病动物血浆α -生育酚水平。因此，研究α - ttp表达的调控因子可能为阐明维生素E的抗氧化机制提供重要线索。
Vitamin E, a critical fat-soluble vitamin antioxidant, is expressed on cell membranes and prevents propagation of lipid peroxidation. alpha-Tocopherol transfer protein (alpha-TTP) is a cytosolic protein located in the hepatocytes that acts as the principal regulator of the circulating alpha-tocopherol levels. Type 2 diabetes is a metabolic disorder characterized by hyperglycemia, caused by insulin resistance. Lipid peroxidation promotes the clinical progression and development of complications in type 2 diabetes. Results of animal and human experiments on the vitamin E status in diabetes are conflicting. The present study was conducted with the objective of investigating the vitamin E status and alpha-TTP expression in Goto-Kakizaki (GK) rats, a model of type 2 diabetes. In diabetic GK rats, increases of the alpha-tocopherol levels in the plasma and liver were observed as compared with the levels in the controls. No alternation in the CuZn-superoxide dismutase (SOD) or Mn-SOD gene expression was found in the liver of GK rats as compared with that in the controls. The GK rats showed an increase of the hepatic expression of the alpha-TTP gene as compared with the level in the controls. It can be suggested that the increased hepatic alpha-TTP gene expression levels may influence plasma alpha-tocopherol levels in the diabetic animals. Hence, investigation of the regulatory factors of alpha-TTP expression may provide important clues to highlighting the antioxidant mechanisms of vitamin E.