铜缺乏对大鼠铁代谢影响的研究

Effect of copper deficiency on iron metabolism in rats

目的研究铜缺乏对大鼠铁营养状况和肝脏转铁蛋白受体mRNA及铁调素mRNA的影响。方法 48只雄性SD大鼠按体重随机分为4组,每组12只,正常对照组(Ⅰ组),铁正常铜完全缺乏组(Ⅱ组),铁正常铜轻度缺乏组(Ⅲ组),铁/铜轻度缺乏组(IV组)。喂饲8周后处死,取大鼠肝脏、脾脏和血清,测定血红蛋白,血清铜、血清铁、血清转铁蛋白受体、血清铁蛋白、肝脏铁和铜含量、脾脏铁和铜含量,并用逆转录-聚合酶链反应(RT-PCR)法检测各组大鼠肝脏转铁蛋白受体(TfR)和铁调素mRNA的表达水平。结果与正常对照组相比,铜缺乏使血清铁、血清铁蛋白含量显著降低(P<0.05),血清转铁蛋白受体水平、肝脾脏铁含量显著升高(P<0.05),铜缺乏时肝脏TfRmRNA表达增强,而肝脏铁调素mRNA表达下降。结论铜缺乏可能通过影响铁吸收、储存、转运来影响体内铁的营养状况。铜缺乏对大鼠铁调素mRNA的表达与IRE-IRP途径调节的转铁蛋白受体mRNA的表达均产生影响。

Objective To study the effect of copper deficiency on the nutritional status of iron,the expression of hepcidin mRNA and transferrin receptor mRNA in rats.Methods Forty eight clean male SD rats were randomly divided into four groups according to body weight; and there were 12 rats in each group.The groups are normal iron and copper control group （groupⅠ）,normal iron and copper deficiency group （groupⅡ）,normal iron and copper slightly deficient group （ group Ⅲ）,both iron and copper slightly deficient group （ group Ⅳ）.Serum,liver and spleen of rats were collected by the end of 8th week.Serum copper,serum iron,hemoglobin,serum transferrin receptor,serum ferritin,liver iron and liver copper,spleen iron and spleen copper were determined.The expression of liver transferring receptor mRNA and hepcidin mRNA were measured by reverse transcription polymerase chain reaction （RT-PCR） method.Results Compared with the controls,the contents of serum iron and serum ferritin decreased （P〈0.05）,but the level of serum transferrin receptor and the content of iron in liver and spleen increased significantly under copper deficiency.The expression of transferrin receptor mRNA in liver increased but the expression of hepcidin mRNA in liver decreased significantly under copper deficiency （P〈0.05）.Conclusion The nutritional status of iron may be affected by copper deficiency through influencing the absorption,storage and transportation of iron.Under the condition of copper deficiency,the expression of hepcidin mRNA in liver was lowered and the expression of transferrin receptor mRNA was enhanced through the way of iron response elementiron regulatory protein （IRE—IRP） to regulate iron metabolism.