短链酰基辅酶A脱氢酶在高血压血管重构中的作用

摘要

目的:研究短链酰基辅酶A脱氢酶(short-chain acyl-CoA dehydrogenase,SCAD)在高血压血管重构中的变化,探讨SCAD与高血压血管重构之间的关系.方法:采用游泳耐力训练方式训练16周龄的自发性高血压大鼠(spontaneously hypertensive rats,SHR)和健康Wistar大鼠8周,分别以24周龄的SHR和Wistar大鼠作为实验对照,定期测量鼠尾收缩压,测定各组大鼠胸主动脉血管腔内径和血管壁中层厚度、SCAD的mRNA和蛋白表达水平、SCAD酶活性的变化、ATP和ROS水平及血清和胸主动脉游离脂肪酸含量.结果:与Wistar组比较,SHR组大鼠血压升高,血管腔内径减小,血管壁中层厚度增大,血管壁中层厚度与血管腔内径比值增大;与SHR组相比,SHR游泳组血压下降,血管腔内径增大,血管壁中层厚度减小,血管壁中层厚度与血管腔内径比值减小(P<0.05).与Wistar组比较,SHR组大鼠主动脉SCAD的mRNA和蛋白表达水平显著下调,主动脉中SCAD酶活性下降,ATP含量降低,血清和主动脉游离脂肪酸含量明显增加,ROS含量增加;分别与Wistar组和SHR组比较,Wistar游泳组和SHR游泳组主动脉SCAD的mRNA和蛋白表达水平均明显上调,主动脉中SCAD的酶活性增高,ATP含量增加,血清和主动脉的游离脂肪酸含量明显减少,ROS含量减少.结论:主动脉SCAD的表达下调可能与高血压血管重构密切相关.游泳运动可能通过上调SCAD表达,从而逆转高血压血管重构.%AIM:To investigate the changes of short-chain acyl-CoA dehydrogenase(SCAD)in hypertensive vascular remodeling and to explore the relationship between SCAD and vascular remodeling in hypertension.METHODS:The spontaneously hypertensive rats(SHR;24 weeks old)and Wistar rats(24 weeks old)were used as experimental con-trol groups.The SHR and Wistar rats of 16 weeks old were trained by swimming as experimental groups.The systolic pres-sure was measured periodically.The thickness of vascular wall and the diameter of the vascular lumen were measured.The contents of ROS and ATP,the enzyme activity of SCAD, and the expression of SCAD at mRNA and protein levels in the aorta were determined.The free fatty acid in the serum and aorta was also measured.RESULTS:Compared with Wistar group,the diameter of vascular lumen decreased in SHR group.The thickness of vascular wall,the ratio of vascular wall and the diameter of vascular lumen,and the blood pressure in SHR group were increased significantly(P<0.05).Com-pared with SHR group,the diameter of vascular lumen increased in SHR +swim group.The thickness of vascular wall,the ratio of vascular wall and the diameter of vascular lumen,and the blood pressure in SHR +swim group were decreased sig-nificantly.Compared with control group, the expression of SCAD at mRNA and protein levels, the enzyme activity of SCAD,and the content of ATP were decreased in SHR group.However,the free fatty acid in the serum and aorta,and the content of ROS in the aorta were increased in SHR group.The expression of SCAD at mRNA and protein levels,the en-zyme activity of SCAD,the content of ATP were increased in Wistar +swim group and SHR +swim group.However, the free fatty acid in serum and aorta,and the content of ROS in the aorta were decreased in Wistar +swim group and SHR+swim group.CONCLUSION: Decrease in SCAD expression may be associated with hypertensive vascular remodeling. Swimming training can reverse hypertensive vascular remodeling by increasing the expression of SCAD in the aorta.