Rho连接激酶在模拟失重大鼠股动脉收缩中的作用

Role of Rho associated kinase in contraction of femoral artery from rats underwent simulated microgravity

目的通过测量Rho连接激酶(Rhoassociatedkinase,ROK)蛋白的含量来研究其在模拟失重大鼠股动脉收缩中可能发挥的作用。方法采用14d尾部悬吊大鼠(-30°)模拟失重效应,Wistar大鼠被随机分成两组:悬吊组(TS14d)和对照组(CON),利用离体血管环灌流技术和WesternBlotting技术检测股动脉平滑肌中ROK蛋白的表达和肌球蛋白轻链(MLC)磷酸化水平的变化。结果与对照组相比,14d尾部悬吊使大鼠股动脉中ROCK-Ⅱ蛋白的表达显著增高,ROCK-Ⅰ的表达量差异没有显著性;加入苯肾上腺素(PE)后,对照组股动脉MLC磷酸化水平显著高于悬吊组。结论14d尾部悬吊后大鼠股动脉中RhoA-ROK通路的活性增强,这可能在一定程度上对平滑肌收缩力减弱起到了代偿作用。

Objective To determine the role of Rho associated kinase （ROK） in contraction of femoral artery from rats underwent tail suspension. Methods Male Wistar rats （n= 32） were randomly divided into control group （CON） and 14-day tail suspension group （TS14d）. -30° tail suspension was used to simulate the physiological effects of microgravity. Vascular ring bathing technique and Western Blotting technique were used to determine the changes of ROK content and the phosphorylation levels of myosin light chain （MLC） in femoral artery. Result The ROCK-Ⅱ protein expression levels in femoral arteries from TS14d rats were significantly higher than that of controls, whereas the difference between levels of ROCK-Ⅰ protein expression of two groups was nonsignificant. The phosphorylation levels of MLC in the presence of phenylephrine （PE） in TS14d rats was significantly lower than that of controls- Conclusion Tail suspension for 14 days enhances ROK activity in rat femoral arteries, which may compensat the lowered contractility of smooth muscle in certain degree。