氯沙坦对大鼠废用性骨骼肌不同肌球蛋白亚型基因表达的影响

Effects of Losartan on the Myosin Isoforms Genes Expression in Rat Soleus Atrophy Induced by Tail-Suspension

目的探讨氯沙坦对大鼠废用性骨骼肌不同肌球蛋白亚型基因表达的影响。方法采用大鼠尾部悬吊2周建立废用性肌肉萎缩模型,药物干预组给予氯沙坦灌胃2周。采用实时荧光定量PCR测试比目鱼肌中不同肌球蛋白亚型基因表达量,冰冻切片测试骨骼肌中毛细血管密度和毛细血管数/肌纤维数比值。结果 (1)与C组相比,TS组大鼠体重、比目鱼肌重量和相对重量均降低(P<0.05或P<0.01),与TS组相比,TD组大鼠体重、比目鱼肌重量和相对重量均升高(P<0.05);(2)与C组相比,TS组、TD组大鼠比目鱼肌毛细血管密度和毛细血管数/肌纤维数比值显著下降(P<0.05),TD组与TS组相比有显著性增加(P<0.05);(3)与C组相比,TS、TD组的MHC I mRNA、MHCⅡa mRNA、MHCⅡb mRNA表达量均降低(P<0.01、P<0.05、P<0.05),TD组的MHC I mRNA表达量与TS组相比升高(P<0.05)。结论大鼠尾部悬吊14天,比目鱼肌出现明显萎缩。服用氯沙坦可通过改善比目鱼肌的血液循环,提高MHC I mRNA的表达,具有一定的抑制骨骼肌萎缩作用。

Objective To probe into the effects of losartan on the myosin isoforms genes expression in tail-suspension rats＇ skeletal muscle. Methods 24 SD rats （8-week） were divided into four groups randomly, and tail-suspension or Losartan administration was the experimental treatment according to the different group. The research measured the the levels of MHC isoforms mRNA in soleus by real time fluorescence quantification PCR. Results After 14-day tail-suspension, the body weight and soleus mass in the TS group reduced comparing with the control group （P 〈0. 05 or P 〈0. 01 ） ,and the two indexes mentioned above in the TD group were more than TS group＇s （ P 〈 0. 05 ）. The levels of expression of MHCI mRNA in the TS and TD group reduced respectively as compared with the control group （ P 〈 0.01 ） , and the levels of expression of MHCI-mRNA in TD group were higher than TS group （ P 〈 0. 05 ）. The levels of expression of MHC Ⅱ a mRNA in the TS and TD group reduced respectively as compared with the control group（ P 〈 0. 05 ） , and so did the levels of expression of MHC H b mRNA in the two groups （P 〈 0. 05 ）. Conclusion After 14 days tail-suspension, the levels of expression of MHCI mRNA, MHC Ⅱ a mRNA and MHC Ⅱb mRNA in the soleus decreased. Suspended rats with losartan may increase the expression of MHCI mRNA and inhibit the soleus atrophy by improving blood circulation of the muscle.