ROK在14 d尾部悬吊大鼠股动脉收缩中的作用

目的研究Rho连接激酶(Rho associated kinase,ROK)在14 d尾部悬吊大鼠股动脉收缩中的作用.方法采用14 d尾部悬吊大鼠(-30°)模拟失重效应,Wistar大鼠被随机分成2组自由活动组(对照组,CON)和悬吊组(TS14d),利用离体血管环灌流技术检测ROK抑制剂Y-27632对KCI、苯肾上腺素(PE)和U-46619诱导的大鼠股动脉收缩反应性的影响.结果 与对照组相比,悬吊组股动脉对68 mmol/L KCl和10-5 mol/L PE的收缩反应性显著下降,而对10-6 mol/L U-46619诱导的收缩反应下降不显著;在68 mmol/L KCI诱导的收缩中,Y-27632对收缩的抑制效应随剂量的增加而增强且在悬吊组更强,在Y-27632由10-6 mol/L增加到10-5 mol/L时,悬吊组股动脉的紧张性收缩(tonic contraction)几乎被完全抑制,在PE和U-46619诱导的收缩中,Y-27632对收缩的抑制效应在悬吊组较强;在Y-27632作用下,悬吊组收缩力下降的幅值较高,但下降的幅值在KCI和PE诱导的收缩中没有显著性差异.结论 14 d尾部悬吊增强了大鼠股动脉RhoA-ROK通路的活性,这种活性的增强可能在一定程度上对平滑肌收缩力的减弱起到了代偿作用.

Role of ROK in Contraction of Rat Femoral Arteries after 14 d Tail Suspension

Objective: To determine the role of Rho associated kinase (ROK) in contraction of rat femoral arteries after 14 d tail suspension. Method: Male Wistar rats were randomly divided into control group (CON) and 14 d -30 degrees tail suspension group (TS14d). Analysis was performed on the contractile responses of perfused femoral arterial rings from both TS14d and CON rats to KCl, phenylephrine (PE), and U-46619 in the presence of Y-27632. Result: Arterial rings from TS14d rats displayed a reduced contractile response to KCl and PE but not significantly to U-46619. In the response to KCl, Y-27632 caused a concentration-dependent relaxation and significantly larger decrease of contraction in tissues from TS14d rats. Y27632 nearly abolished the tonic component of KCl-induced contraction when its dose was increased from 10(-6)mol/L to 10(-5) mol/L. It had also an inhibitive effect on the PE and U-46619-induced contraction and caused significantly larger decrease in U-46619 but not in KCl or PE induced contraction in tissues from TS14d rats. Conclusion: ROK activity may be enhanced and play a compensational role in rat femoral arteries after TS14d.