运动性低血色素形成中大鼠十二指肠铁吸收蛋白HCP1、DMT1及FPN1表达的动态变化

摘要

目的:研究运动性低血色素形成中大鼠十二指肠铁转运蛋白血红素转运蛋白1 (heme carrier protein 1,HCP1)、二价金属离子转运体1(divalent metal transporter1,DMT1)及膜铁转运蛋白1(ferroportin1,FPN1)表达的动态变化,探讨运动性低血色素的发生机制.方法:36只雄性Wistar大鼠随机分为对照组和运动组.运动组大鼠进行为期5周、6 d/周、坡度为0、速度30 m/min的递增负荷跑台训练.前2周每天训练1次,时间从1 min开始,每次递增2 min.从第3周开始,每天训练2次.分别于运动第3、4、5周末取材,采用血细胞自动分析仪测定血红蛋白(Hb)含量；Western Blot检测十二指肠上皮细胞HCP1、DMT1及FPN1表达.结果:(1)长时间大强度运动后大鼠Hb含量逐渐降低.运动组3周末Hb与其对照组相比有下降趋势,4周和5周末显著低于其对照组(P＜ 0.05,P＜0.01).(2)运动组大鼠3周末小肠上皮细胞HCP1、DMT1及FPNl表达均显著高于其对照组(P＜0.01),4周末与其对照组相比均无显著差异(P＞0.05),5周末均显著低于对照组(P＜0.01).结论:大强度运动开始阶段,机体通过增加肠铁吸收维持运动机体对铁的需求,随运动时间延长,机体肠铁吸收能力降低,这是引发运动性低血色素的重要原因之一.%Objective To investigate the expression of heme carrier protein 1 (HCP1) ? Divalent metal transporter 1 (DMT1) and ferroportin 1 (FPN1) in rats' duodenal epithelium and illuminate the regulatory mechanism of iron absorption in rats with exercise-induced hypochrosis. Methods ThirtySix male Wistar rats were randomly divided into two groups: the control group (CG) and the exercise group (EG) . Rats in exercise group undertook 5-week treadmill exercise at the speed of 30m/ min with increasing exercise duration by 2min each section, once a day for the first and the second week and twice a day for the last 3 weeks, 6d/week. The rats were sampled after 3-week, 4-week, and 5-week training respectively. The expression of DMT 1, HCP1 and FPN1 were examined by Western blot after exercise. Results ( 1) The level of Hb in EG after 3-week training decreased comparing to that in CG, but not significantly. While compared with CG, The level of Hb were significantly decreased in EG after 4-week training (P < 0.05) . The level of Hb were significantly decreased in EGthan those in CG after 5-week training (P<0.01) . (2) The expressions of DMT 1, HCPlandFPNl were significantly increased in EG compared to those in CG after 3-week training (P < 0.01) . While compared with CG, the expressions of the three proteins showed no differences in EG after 4-week training. The expressions of DMT 1, HCP1 and FPN1 were significantly decreased in EG than those in CG after 5-week training (P < 0.01) . Conclusion With the extension of exercise time, intestinal iron absorbing showed a time course changes , might be an important reason for the cause of exercise-associated anemia.