Robinson Austin T, Fancher Ibra S, Sudhahar Varadarajan, Bian Jing Tan, Cook Marc D, Mahmoud Abeer M, Ali Mohamed M, Ushio-Fukai Masuko, Brown Michael D, Fukai Tohru, Phillips Shane A
Department of Physical Therapy, University of Illinois at Chicago, Chicago, Illinois;
Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois.
Am J Physiol Heart Circ Physiol. 2017 May 1;312(5):H896-H906. doi: 10.1152/ajpheart.00684.2016. Epub 2017 Feb 24.
High blood pressure has been shown to elicit impaired dilation in the vasculature. The purpose of this investigation was to elucidate the mechanisms through which high pressure may elicit vascular dysfunction and determine the mechanisms through which regular aerobic exercise protects arteries against high pressure. Male C57BL/6J mice were subjected to 2 wk of voluntary running (~6 km/day) for comparison with sedentary controls. Hindlimb adipose resistance arteries were dissected from mice for measurements of flow-induced dilation (FID; with or without high intraluminal pressure exposure) or protein expression of NADPH oxidase II (NOX II) and superoxide dismutase (SOD). Microvascular endothelial cells were subjected to high physiological laminar shear stress (20 dyn/cm) or static condition and treated with ANG II + pharmacological inhibitors. Cells were analyzed for the detection of ROS or collected for Western blot determination of NOX II and SOD. Resistance arteries from exercised mice demonstrated preserved FID after high pressure exposure, whereas FID was impaired in control mouse arteries. Inhibition of ANG II or NOX II restored impaired FID in control mouse arteries. High pressure increased superoxide levels in control mouse arteries but not in exercise mouse arteries, which exhibited greater ability to convert superoxide to HO Arteries from exercised mice exhibited less NOX II protein expression, more SOD isoform expression, and less sensitivity to ANG II. Endothelial cells subjected to laminar shear stress exhibited less NOX II subunit expression. In conclusion, aerobic exercise prevents high pressure-induced vascular dysfunction through an improved redox environment in the adipose microvasculature. We describe potential mechanisms contributing to aerobic exercise-conferred protection against high intravascular pressure. Subcutaneous adipose microvessels from exercise mice express less NADPH oxidase (NOX) II and more superoxide dismutase (SOD) and demonstrate less sensitivity to ANG II. In microvascular endothelial cells, shear stress reduced NOX II but did not influence SOD expression.
高血压已被证明会导致血管舒张功能受损。本研究的目的是阐明高血压引发血管功能障碍的机制,并确定规律有氧运动保护动脉免受高血压影响的机制。将雄性C57BL/6J小鼠进行2周的自愿跑步(约6公里/天),以与久坐不动的对照组进行比较。从小鼠身上分离出后肢脂肪阻力动脉,用于测量血流诱导的舒张(FID;有或无高腔内压力暴露)或NADPH氧化酶II(NOX II)和超氧化物歧化酶(SOD)的蛋白表达。对微血管内皮细胞施加高生理性层流切应力(20达因/平方厘米)或静态条件,并用血管紧张素II + 药理抑制剂进行处理。分析细胞以检测活性氧(ROS),或收集细胞进行Western印迹法测定NOX II和SOD。运动小鼠的阻力动脉在高压暴露后显示出保留的FID,而对照小鼠动脉中的FID受损。抑制血管紧张素II或NOX II可恢复对照小鼠动脉中受损的FID。高血压会增加对照小鼠动脉中的超氧化物水平,但运动小鼠动脉中不会增加,运动小鼠动脉表现出更强的将超氧化物转化为过氧化氢的能力。运动小鼠的动脉表现出较少的NOX II蛋白表达、更多的SOD同工型表达以及对血管紧张素II的敏感性降低。受到层流切应力作用的内皮细胞表现出较少的NOX II亚基表达。总之,有氧运动通过改善脂肪微血管中的氧化还原环境来预防高血压诱导的血管功能障碍。我们描述了有助于有氧运动赋予血管抗高血管内压保护作用的潜在机制。运动小鼠的皮下脂肪微血管表达较少的NADPH氧化酶(NOX)II和较多的超氧化物歧化酶(SOD),并且对血管紧张素II的敏感性较低。在微血管内皮细胞中,切应力降低了NOX II,但不影响SOD表达。