模拟失重所致动脉结构和功能重建的机理尚未完全阐明，故尚无满意防护措施。近年研究提示：多条通路参与失重/模拟失重下动脉结构和功能重塑，而RhoA/Rho激酶通路可能作为众多通路的交汇点，在动脉重建中发挥关键作用。本研究拟以大鼠尾部悬吊模拟失重影响，进行以下工作：①观测短、中、长期悬吊大鼠动脉RhoA、Rho激酶表达水平，确定其改变与模拟失重时程是否相关；②检测RhoA/Rho激酶通路关键分子的表达及磷酸化水平，确定其活性改变的途径；③观察RhoA/Rho激酶通路与动脉反应性、VSMCs增殖与凋亡、L-Ras系统、ROS通路、NOS通路及炎症反应的关系，确定其对动脉结构与功能的影响；④观测Rho激酶抑制剂是否能影响上述各通路的改变，探讨RhoA/Rho激酶通路是否动脉结构和功能重塑的关键作用分子。本工作对阐明航天失重下动脉重建的机理具有理论意义，亦可能为载人航天医务保障新思路提供实验依据。

The definite mechanism underlying structural and functional remodeling of artery system induced by microgravity still remains unclear. Thus, there's still no pertinent countermeasure for the moment. Results from recent studies have indicated that multiple pathways could be involved in the process of artery remodeling induced by microgravity/simulated microgravity, in which the RhoA/Rho kinase pathway may play a central role as the intersection of all these pathways probably involved. To test this hypothesis, we take the tail-suspended rat as the animal model of simulated microgravity and then carry out the following procedures: ①test the level of RhoA and Rho kinase expression of the artery system in rats induced by short-, medium- and long-termed simulated microgravity, and determine the correlation between the changes and time course of simulated microgravity; ②detect the expression and phosphorylation of the key molecules in RhoA/Rho kinase pathway, and ascertain the mechanisms underlying their alterations; ③observe the relationship between RhoA/Rho kinase pathway and the arterial vasoreactivity, proliferation and apoptosis of VSMCs, L-Ras system, ROS, NOS and inflammatory responses, and determine the impact of this pathway on the structure and function of the artery system; ④detect if the specific inhibitor of Rho kinase could prevent the alterations of the pathways mentioned above, and finally confirm if RhoA/Rho kinase pathway plays the pivotal role as the intersection in the structural and functional remodeling of artery system. Our study supplies significant importance for explaining the mechanisms involved in the arterial remodeling induced by microgravity, and proposes a new idea for the medical guarantee in the activity of manned space flight.