长期有氧运动和饮食铁含量对雌性大鼠血液铁和海马贮存铁的影响

Effect of long-term aerobic exercise and dietary iron content on hematological and hippocampal iron in female rats

目的观察饮食铁含量和长期有氧运动对雌性大鼠血液铁状态和海马非血红素铁(NHI)贮存的影响,探讨外周铁浓度与脑铁浓度的变化关系。方法采用断乳雌性SD大鼠71只,随机分为3组:饮食低铁含量组(12 mg/kg),饮食标准铁含量组(45 mg/kg)和饮食高铁含量组(1 000 mg/kg),其中每一组再分为运动组和静息组。用相应的铁含量饲料喂养1个月后,运动组进入游泳期,每周5 d,每天1次,每次30 min,持续3个月。静息组除不进行运动外,其余处理与对应运动组相同。在末次运动后,所有大鼠禁食24 h,用戊巴比妥钠麻醉后静脉取血,测定红细胞相关指标和血清铁状态指标;断头取全脑,冰上快速分离出海马,测定海马NHI含量。结果与标准铁含量静息组比,低铁含量静息组血红蛋白(Hb)、红细胞压积(HCT)、平均红细胞体积(MCV)和平均红细胞血红蛋白量(MCH)均降低(P<0.05),红细胞分布宽度(RDW)和血浆总铁结合力(TIBC)升高(P<0.05)。低铁含量饮食时(ID),与静息组比,运动组Hb、HCT显著升高(P<0.01),海马NHI含量升高(P<0.05),血清铁(SI)、转铁蛋白饱和度(TS)均显著降低(P<0.01)。高铁含量饮食时(SU),与静息组比,运动组血浆TIBC升高(P<0.05),TS降低(P<0.05)。结论低铁含量饮食导致雌性大鼠出现血液低铁状态,机体对于饮食铁不足有适应性调节;低铁饮食下长期低强度运动会加重雌性大鼠血液低铁状态,并且导致脑内海马铁贮存水平升高。

[ Objective] To obverse the effect of dietary iron content and long-term aerobic exercise on blood iron status and hipp- ocampal non-heme iron （ NHI ） reposition in female rats, explore the relationship between peripheral iron concentration and brain iron concentration. [ Methods] The study included 71 female Spragne-Dawley weanling rats, which were randomly divided into three groups： dietary iron deficiency group （ 12 mg/kg）, dietary iron sufficiency group （45 mg/kg） and dietary iron-supplemented group { 1 000 mg/kg） , and the animals in each group was further assigned into an exercise group and a sedentary group. After feeding for 1 month, the rats in each exercise group entered a swimming program that swan 1/2 hours per day, 5 days per week for 3 months. The rats in the sedentary groups were given the same treatment except swimming. Animals were fasted for 24 hours after the last exercise regimen and fasting blood samples were collected under pentobarbital anesthesia for analyzing related indexes of red blood ceils and serum iron. The brain was removed immediately, and the hippocampus was isolated to determine the NHI contents. [ Results] The levels of hemoglobin （ Hb）, hematocrit（ HTC）, mean corpuscular volume （MCV） and mean corpuscular hemoglo- bin （ MCH ） in iron deficiency sedentary group decreased as compared with those in iron sufficiency sedentary group （ P 〈 0.05 ）, but the levels of red blood cell distribution width （RDW） and total iron binding capacity （TIBC） increased （ P 〈 0.05 ）. In dietary iron deficiency group, the higher levels of Hb, HCT and hippocampal NHI in exercise group were observed as compared to sedentary group, but the levels of serum iron （ SI ） and transferring saturation （ TS ） decreased significantly （ P 〈 0.01 ）. In dietary ironsupplemented group, the levels of TIBC in exercise group was higher than that in sedentary group （ P 〈 0.05 ） , while the level of TS was lower than that in sedentary group （P 〈 0.05）. [ Conclusion] The deficiency iron diet could lead to low blood iron status, the changes might be an adaptation due to hematologic responded to deficiency iron diet. In low-iron dietary, long-term low-intensity exercise could increase low blood iron statue and lead to a higher level of hippocampal NHI.