短、中期尾吊大鼠动脉局部血管紧张素转化酶与糜酶表达的变化

Effects of short-and mid-term tail suspension on expression of ACE and chymase of arteries in rats

目的探讨局部肾素-血管紧张素系统(renin-angiotensin system,RAS)在短、中期尾部悬吊致大鼠动脉差异性适应中的作用。方法采用尾吊1周和4周模拟短期和中期失重影响,取基底动脉和股动脉组织,应用反转录-聚合酶链式反应(RT-PCR)检测血管紧张素转化酶(angiotensin converting enzyme,ACE)和糜酶的mRNA的表达水平,并通过脱氧核糖核酸(DNA)序列测定对PCR结果进行验证。结果与对照组相比,尾吊1周后,基底动脉血管组织ACE的mRNA表达显著增加(P<0.05),糜酶的mRNA表达无明显改变;股动脉血管组织ACE的mRNA表达显著降低(P<0.05),糜酶的mRNA表达无显著改变。悬吊4周后,基底动脉和股动脉血管组织ACE和糜酶的mRNA表达均无显著改变。结论短期模拟失重可引起ACE在不同动脉血管组织差异性表达的改变。提示局部RAS可能在模拟失重致动脉差异性适应中起重要作用。

AIM To explore the role of local renin-angiotensin system （RAS） in differential adaptation of arteries to short- and mid-term simulated weightlessness. METHODS 1- and 4-wk tail-suspended rat models were respectively adopted to simulate short- and mid-term weightlessness. Basilar and femoral arteries were harvested. Reverse transcriptase polymerase chain reaction （RT-PCR） was employed to examine the mRNA expression of angiotensin converting enzyme （ACE） and chymase. The PCR products were further confirmed by DNA sequencing. RESULTS After 1-wk tail suspension, mRNA expression of ACE in basilar arterial tissue increased significantly （ P 〈 0.05 ）, but there were no obvious changes in mRNA expression of chymase. In femoral arterial tissue, mRNA expression of ACE decreased significantly （ P 〈 0.05 ） and mRNA expression of chymase changed insignificantly as compared with that of control level. After 4-wk tail suspension, no significant mRNA expression changes of ACE and chymase were observed in both basilar and femoral arterial tissues compared with that in control rats. CONCLUSION Shortbut not mid-term simulated weightlessness may induce differential expression of ACE in different arterial tissues, which indicates local RAS may play a pivotal role in differential adaptation of arteries induced by simulated weightlessness.