Effect of behavioral stress on coronary artery relaxation altered with aging in BHR.
Effect of behavioral stress on coronary artery relaxation altered with aging in BHR.
复制标题
BHR 中行为压力对冠状动脉舒张的影响随着年龄的增长而改变。
DOI：
10.1152/ajpregu.1999.276.2.r435
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Fuchs,LC
中科院分区：
文献类型：
--
作者：
Giulumian,AD;Clark,SG;Fuchs,LC
行为压力和衰老与血管疾病的增加有关。本研究确定了年轻（3个月）和老年（18个月）雄性交界性高血压大鼠（BHR）暴露于10天（2小时/天）的喷气压力下，离体冠状动脉（300-350 μm）内皮依赖性松弛变化的机制。单独衰老并没有定量改变内皮依赖性乙酰胆碱（ACh）松弛，但确实改变了促进ACh松弛的机制，这在很大程度上依赖于年老而不是年轻BHR血管中的一氧化氮合酶（NOS）。与年轻对照BHR相比，行为应激导致年轻应激小鼠血管中乙酰胆碱的松弛增强，这依赖于NOS。相反，与对照组BHR相比，老年应激组冠状动脉中乙酰胆碱的松弛度降低。在旧对照BHR的血管中，存在由K+通道打开介导的不依赖nos的松弛成分，这在旧应激BHR的血管中是不存在的。超氧阴离子清除剂铁部分恢复松弛，而环加氧酶的抑制很大程度上恢复了旧应激BHR血管中乙酰胆碱的松弛。综上所述，行为压力的影响具有年龄依赖性。在年轻BHR中，乙酰胆碱诱导的冠状动脉舒张以nos依赖的方式增强，而在老年BHR中，由于超氧阴离子、血管收缩剂环加氧酶产物和K+通道介导的舒张丧失，冠状动脉舒张受损。
Behavioral stress and aging are associated with an increase in vascular disease. This study determined the mechanisms contributing to changes in endothelium-dependent relaxation of isolated coronary arteries (300–350 μm) induced by exposure to 10 days of air-jet stress (2 h/day) in young (3 mo) and old (18 mo) male borderline hypertensive rats (BHR). Aging, alone, did not alter endothelium-dependent relaxation to acetylcholine (ACh) quantitatively but did alter the mechanisms contributing to relaxation to ACh, which was largely dependent on nitric oxide synthase (NOS) in vessels from old, but not young, BHR. Behavioral stress resulted in an enhanced relaxation to ACh that was dependent on NOS in vessels from young stressed compared with young control BHR. Conversely, relaxation to ACh was reduced in coronary arteries from old stressed compared with old control BHR. In vessels from old control BHR, there was an NOS-independent component of relaxation mediated by opening of K+channels that was absent in vessels from old stressed BHR. The superoxide anion scavenger, tiron, partially restored relaxation, and inhibition of cyclooxygenase largely restored relaxation to ACh in vessels from old stressed BHR. In summary, the effect of behavioral stress was age dependent. ACh-induced relaxation of coronary arteries was enhanced in an NOS-dependent manner in young BHR and was impaired in old BHR due to superoxide anions, vasoconstrictor cyclooxygenase products, and a loss of K+channel-mediated relaxation.