补充维生素A对缺铁性贫血大鼠妊娠后贫血情况和子代的影响

Effect of vitamin A supplementation on gestational anemia status of iron deficiency anemia rats and their offspring

目的探讨补充维生素A对缺铁性贫血(IDA)大鼠妊娠期贫血的改善作用,以及对子代的生长发育和铁代谢的影响。方法(1)将30只雌性大鼠随机分为对照组(n=10)和缺铁组(n=20),分别给予标准饲料、低铁饲料喂养。4周后,将雌性大鼠与雄性大鼠合笼,确认受孕后将缺铁组大鼠随机分为模型组(n=10)和治疗组(n=10)。治疗组雌鼠灌胃维生素A,其他两组灌胃等量油溶液,直至分娩。(2)检测分组喂养前、分组喂养4周后、孕末期(孕17 d)雌鼠的血红蛋白水平、血细胞比容(HCT)、平均红细胞体积(MCV)、平均红细胞血红蛋白含量(MCH)、平均红细胞血红蛋白浓度(MCHC)、红细胞分布宽度(RDW),以及血清铁蛋白、可溶性转铁蛋白受体(sTfR)水平。分娩后处死雌鼠,取其垂体和肝脏组织并分别检测生长激素(GH)和胰岛素样生长因子1(IGF-1)的mRNA相对表达水平。(3)记录各组仔鼠存活率和存活仔鼠的出生体重。各组取10只仔鼠处死,检测其血清铁蛋白和sTfR水平,以及肝脏中转铁蛋白受体1(TfR1)、铁蛋白轻链(FTL)、铁调素的蛋白相对表达水平。结果(1)分组喂养4周后,缺铁组雌鼠血红蛋白、HCT、MCV、MCH、MCHC和血清铁蛋白水平均低于分组喂养前和对照组,而RDW和血清sTfR水平高于分组喂养前和对照组(均P<0.05)。在孕末期,对照组、治疗组、模型组雌鼠血红蛋白、HCT、MCV、MCH、MCHC和血清铁蛋白水平均依次降低,RDW和血清sTfR水平依次升高(均P<0.05)。对照组、治疗组、模型组雌鼠垂体组织中GH和肝组织中IGF-1的mRNA相对表达水平均依次降低(均P<0.05)。(2)对照组、治疗组、模型组仔鼠的存活率、存活仔鼠出生体重,以及血清铁蛋白水平、肝组织中FTL和铁调素的蛋白相对表达水平均依次降低,而血清sTfR水平和肝组织中TfR1的蛋白相对表达水平均依次升高(均P<0.05)。结论维生素A或可通过调节GH/IGF-1轴改善IDA雌鼠的妊娠期贫血状况,也可通过调节子代体内铁代谢相关蛋白的表达维持铁代谢平衡,从而促进子代的生长与发育。

Objective To investigate the improvement effect of vitamin A supplementation on gestational anemia in rats with iron deficiency anemia(IDA)as well as its effect on the growth and development and iron metabolism of their offspring.Methods(1)Thirty female rats were randomly divided into control group(n=10),which were given standard feed,and iron deficiency group(n=20),which were given low-iron feed.Four weeks later,female and male rats were caged together.After being pregnant,rats in the iron deficiency group were randomly divided into model group(n=10)and treatment group(n=10).Female rats in the treatment group were intragastrically given vitamin A until delivery,while rats in the other two groups were intragastrically given the same amount of oily solution until delivery.(2)Multiple indices of female rats were detected before feeding based on group,four weeks after feeding based on group,and at the end of pregnancy(on the 17th day of pregnancy),including the hemoglobin level,hematocrit(HCT),mean corpuscular volume(MCV),mean corpuscular hemoglobin(MCH),mean corpuscular hemoglobin concentration(MCHC),red blood cell distribution width(RDW),as well as serum levels of ferritin and soluble transferrin receptor(sTfR).Female rats after the delivery were killed,their pituitary gland and liver tissues were harvested,and the relative expression levels of growth hormone(GH)and insulin-like growth factor 1(IGF-1)mRNAs were detected.(3)The survival rate of newborn rats as well as the birth weights of surviving newborn rats was recorded in each group.Ten newborn rats selected from each group were killed to detect their serum levels of ferritin and sTfR as well as their relative expression levels of transferrin receptor 1(TfR1),ferritin light chain(FTL),and hepcidin proteins in the liver.Results(1)Four weeks after feeding based on group,female rats'hemoglobin,HCT,MCV,MCH,and MCHC were decreased,serum ferritin level was lower,and RDW and serum sTfR level were higher in the iron deficiency group than those before feeding based on group and in the control group(all P<0.05).At the end of pregnancy,female rats'hemoglobin,HCT,MCV,MCH,MCHC,and serum ferritin level decreased while RDW and serum sTfR level increased in the order of the control group,the treatment group and the model group(all P<0.05).Female rats'relative expression levels of GH mRNA in pituitary gland tissues and IGF-1 mRNA in liver tissues decreased in the control group,treatment group and model group successively(all P<0.05).(2)Newborn rats'survival rate,surviving newborn rats'birth weights,and serum ferritin level,relative expression levels of FTL and hepcidin proteins in liver tissues decreased while surviving newborn rats'serum sTfR level and the relative expression level of TfR1 protein in liver tissues increased in the order of the control group,the treatment group and the model group(all P<0.05).Conclusion Vitamin A can improve the status of gestational anemia of female IDA rats probably by regulating the GH/IGF-1 axis,and can also keep the balance of iron metabolism probably via regulating the expression of iron metabolism-related proteins in the offspring,thus promoting the growth and development of the offspring.