维生素A缺乏对大鼠铁代谢影响

目的 研究维生素A(VA)缺乏对大鼠铁营养状况和肝脏转铁蛋白受体(TfR)mRNA表达的影响.方法 雄性SD大鼠52只,按体重随机分为4组,每组13只,Fe和VA正常对照组(I组),Fe正常VA完全缺乏组(II组),Fe正常VA轻度缺乏组(Ⅲ组),Fe和VA轻度缺乏组(IV组).喂饲8周后处死,测定血清VA、血红蛋白、血清铁、血清转铁蛋白受体、血清铁蛋白、肝脏铁含量,脾脏铁含量,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)mRNA的表达.结果 结果与对照组比较,VA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、脾脏铁含量显著升高(P<0.05),VA缺乏时肝脏TfRmRNA表达显著增强.结论 维生素A缺乏可能通过影响铁吸收、储存、转运变改体内铁的营养状况,VA缺乏时,肝脏可能通过铁调节蛋白(IRE-ⅠRP)途径使TfR mRNA的表达水平增加.

Effect of vitamin A deficiency on iron metabolism in rats

Objective To study the effect of vitamin A(VA)deficiency on nutrit ional status of iron and on mRN A expression of transferrin receptor(TfR)in the liver in rat.Methods Fifty-two male SD rats were divided randomly into four groups according to their body weights and each group included 13 rats.The four groups were normal iron and VA control group,normal iron and severe VA deficient group,normaliron and mild VA deficient group,mildiron and VA deficient group.After raised foreight weeks,the rats were executed and the serum VA,hemoglobin,serum iron,serum transferrin receptor,ser urm ferritin,iron in the liver and spleen were determined.The ex pression of transferr in receptor(T fR)mRNA was examined by reverse transcr iption polymerase chain reaction method(RT-PCR).Results Compared with the control group,VA deficiency groups had a significant decrease in serumiron and serum ferritin(P<0.05),and a significant increase in serum transferrin receptor and iron in the spleen(P<0.05).The high expression level of transferrin receptor mRNA was observed in the liver when VA was deficient.Conclusion VA deficiency may affect absorption,storage and transportation of iron and may enhance the expression level of transferrin receptor mRNA in the liver by IRE-ⅠRP.