右旋糖酐铁对SD大鼠维生素D_(3)代谢水平的影响

EFFECTS OF IRON DEXTRAN ON VITAMIN D METABOLISM IN SD RATS

目的探讨不同剂量的铁对维生素D_(3)(vitamin D_(3), VD_(3))代谢产物25-(OH)D_(3)和1,25-(OH)_(2)D_(3)水平的影响。方法 30只雄性SD大鼠适应性喂养7d后,按体质量随机分为对照组(control, C, n=6正常饲料)和模型组(model, M,n=24缺铁饲料),后者造缺铁性贫血(iron deficiency anemia, IDA)模型。饲喂6w后,M组按血红蛋白(hemoglobin, Hb)水平随机分为缺铁组(deficiency iron, DFe)、低铁组(low iron, LFe)、中铁组(medium iron, MFe)和高铁组(high iron,HFe),分别给予不同剂量的右旋糖酐铁[以(100g·bw·d)含铁量计]:0、1.1、3.3、9.9mg干预。4w后,用8%水合氯醛麻醉大鼠,腹主动脉采血,并取肝、肾组织,将分离的血清、组织分装后于-80℃冻存待测。结果 DFe组大鼠精神状态差,Hb、红细胞(red blood cell, RBC)、血红素(heme)、血清铁(serum iron, SI)、肝铁和肾铁水平明显低于其它4组,转铁蛋白(transferrin, TRF)水平较其它组升高;DFe组与C组比,血清25-(OH)D_(3)和1,25-(OH)_(2)D_(3)水平显著降低(P<0.05),随着干预铁浓度的增加25-(OH)D_(3)和1,25-(OH)_(2)D_(3)水平也随之升高。经相关性分析,25-(OH)D_(3)和1,25-(OH)_(2)D_(3)水平与Hb、RBC、Heme、肝铁、肾铁水平均呈正相关,1,25-(OH)_(2)D_(3)水平与TRF水平呈负相关。结论铁可能参与VD_(3)的羟化过程,补充适量的铁可以促进VD_(3)的活化。

Objective To investigate the effects of different doses of iron on the levels of 25-(OH)D_(3) and 1,25-(OH)_(2) D_(3). Methods Thirty male rats were adaptively fed for 7 days and randomly divided into the control(Control, C, n=6, normal diet) group and the model(Model, M, n=24, iron deficient diet) group according to body weight. The model group was used to establish iron deficiency anemia(iron deficiency anemia, IDA) model. After 6 weeks of feeding, the M group was divided into: iron deficiency group(iron deficiency, DFe), low iron group(low iron, LFe), medium iron group(medium iron, MFe) and high iron group(high iron, HFe) according to the level of hemoglobin(hemoglobin, Hb). Different doses of iron dextran based on iron content(100 g·bw·d)( 0, 1.1, 3.3 and 9.9 mg) were given, respectively. After 4 weeks, rats were anesthetized with 8% chloral hydrate. Blood samples were collected from the abdominal aorta, and liver and kidney tissues were also collected. The serum and tissues were separately packed and frozen at-80℃ for testing. Results The mental state of the rats in the DFe group was poor. The levels of Hb, red blood cell(RBC), heme, serum iron(SI), liver iron and kidney iron were significantly lower than those of the other 4 groups, and transferrin(TRF) was higher than all other groups. Compared with the C group, the levels of 25-(OH)D_(3) and 1,25-(OH)_(2) D_(3) in the serum were significantly lower in the DFe group(P<0.05), and the levels also increased with the increase of iron dose. By correlation analysis, the levels of 25-(OH)D_(3) and 1,25-(OH)_(2) D_(3) were positively correlated with the levels of Hb, RBC, heme, liver iron, kidney iron, and the level of 1,25-(OH)D_(3) was negatively correlated with the level of TRF. Conclusion Iron may be involved in the hydroxylation process of VD_(3), suggesting that supplementing an appropriate amount of iron can promote the activation of VD_(3).