Rush J W, Laughlin M H, Woodman C R, Price E M
Department of Veterinary Biomedical Sciences and Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri 65211, USA.
Am J Physiol Heart Circ Physiol. 2000 Nov;279(5):H2068-76. doi: 10.1152/ajpheart.2000.279.5.H2068.
Coronary arterioles of exercise-trained (EX) pigs have enhanced nitric oxide (NO.)-dependent dilation. Evidence suggests that the biological half-life of NO. depends in part on the management of the superoxide anion. The purpose of this study was to test the hypothesis that expression of cytosolic copper/zinc-dependent superoxide dismutase (SOD)-1 is increased in coronary arterioles as a result of exercise training. Male Yucatan pigs either remained sedentary (SED, n = 4) or were EX (n = 4) on a motorized treadmill for 16-20 wk. Individual coronary arterioles ( approximately 100-microm unpressurized internal diameter) were dissected and frozen. Coronary arteriole SOD-1 protein (via immunoblots) increased as a result of exercise training (2.16 +/- 0.35 times SED levels) as did SOD-1 enzyme activity (measured via inhibition of pyrogallol autooxidation; approximately 75% increase vs. SED). In addition, SOD-1 mRNA levels (measured via RT-PCR) were higher in EX arterioles (1.68 +/- 0.16 times the SED levels). There were no effects of exercise training on the levels of SOD-2 (mitochondrial), catalase, or p67(phox) proteins. Thus chronic aerobic exercise training selectively increases the levels of SOD-1 mRNA, protein, and enzymatic activity in porcine coronary arterioles. Increased SOD-1 could contribute to the enhanced NO.-dependent dilation previously observed in EX porcine coronary arterioles by improving management of superoxide in the vascular cell environment, thus prolonging the biological half-life of NO.
经过运动训练（EX）的猪的冠状动脉小动脉具有增强的一氧化氮（NO·）依赖性舒张功能。有证据表明，NO·的生物半衰期部分取决于超氧阴离子的管理。本研究的目的是检验以下假设：运动训练导致猪冠状动脉小动脉中胞质铜/锌依赖性超氧化物歧化酶（SOD）-1的表达增加。雄性尤卡坦猪要么保持 sedentary（SED，n = 4），要么在电动跑步机上进行EX训练（n = 4），持续16 - 20周。分离并冷冻单个冠状动脉小动脉（未加压时内径约100微米）。运动训练后，冠状动脉小动脉的SOD-1蛋白（通过免疫印迹法）增加（是SED水平的2.16±0.35倍），SOD-1酶活性（通过抑制邻苯三酚自氧化测定）也增加（与SED相比增加约75%）。此外，EX小动脉中的SOD-1 mRNA水平（通过RT-PCR测定）更高（是SED水平的1.68±0.16倍）。运动训练对SOD-2（线粒体）、过氧化氢酶或p67(phox)蛋白水平没有影响。因此，长期有氧运动训练选择性地增加了猪冠状动脉小动脉中SOD-1 mRNA、蛋白和酶活性的水平。SOD-1增加可能通过改善血管细胞环境中超氧化物的管理，从而延长NO·的生物半衰期，有助于先前在EX猪冠状动脉小动脉中观察到的增强的NO·依赖性舒张。
