运动对大鼠腓肠肌一氧化氮含量和铁转运蛋白表达的影响

The Effects of Exercise on the Nitric Oxide and the Expression of Iron Transport Proteins in the Gastrocnemius of Rats

目的观察游泳运动后大鼠腓肠肌一氧化氮(NO)含量及铁转运相关蛋白表达的变化,探讨运动对骨骼肌铁代谢的调节机制。方法20只雌性SD大鼠随机分为对照组和运动组(每天游泳1.5小时,6次/周),每组10只。实验10周后分别采用试剂盒测定两组大鼠腓肠肌和血清一氧化氮合酶(NOS)活性及NO含量,免疫组织化学方法测定腓肠肌二价金属离子转运体1(DMT1)、膜铁转运蛋白1(FP1)和转铁蛋白受体1(TfR1)的表达,分析其平均光密度变化。结果(1)运动组大鼠血清和腓肠肌NO含量和NOS活性均显著高于对照组(P<0.05);(2)运动组大鼠腓肠肌DMT1(IRE)和TfR1表达较对照组显著增加,FP1表达显著减少(P<0.05),而DMT1(non-IRE)表达无明显变化。结果提示运动可能通过增加NOS活性刺激NO合成增加,进而调节腓肠肌铁转运蛋白的表达,提高腓肠肌摄铁能力,以满足运动中机体对铁的需求。

Objective To investigate the effects of exercise on the iron metabolism in the skeletal muscle. Methods Twenty female SD rats （90- 100g） were randomly divided into two groups： control group （CG）, moderate intensity exercised group （MG, swimming 1.5h/day, 6 days/week for 10 weeks）. Serum nitric oxide （NO） and the activity of nitric oxide synthase （NOS） were analyzed by nitrate reductase kit. Quantification of transferrin receptor 1 （TfR1）, divalent metal transporter 1 （DMT1） and ferroportin 1 （FP1） in the gastrocnemius were performed using immunohistology, and the average absorbency density was analyzed. Results （ 1 ） NO and NOS in MG were significantly higher than that in CG （ P 〈 0.05 ）. （2） The expression of DMT1 （IRE） and FP1 was significantly increased in MG as compared with that in CG （ P 〈 0.05）. There was no significant change of DMT1 （non - IRE）. Conclusion The results showed that the increased NO induced by exercise could lead to the change in expression of iron transport proteins in the gastrocnemius, and thus resulting in elevation of iron storage to meet the demand during exercise.