BACKGROUND Limited attention has been paid to the role of beta-adrenergic blocking agents on large artery function/structure, despite being clinically useful for treating many forms of cardiovascular disease. OBJECTIVE To assess long-term consequences of beta-blocker administration on the biomechanical properties, geometry, and histological structure of two major elastic arteries. METHODS Healthy male rats received water with their food, while beta-blockade was produced in rats by adding propranolol in their drinking water. The thoracic aorta and carotid artery were resected after three months for biomechanical (failure and inflation-extension) testing along with geometrical and histological evaluation. RESULTS The thoracic aorta presented increased strength longitudinally in propranolol-treated than untreated rats, resulting from increased adventitial collagen content. The distensibility of carotid artery increased in propranolol-treated rats at low-to-physiologic pressures, resulting from decreased medial collagen content. Structural remodeling was characterized by reduced lumen diameter, wall mass, and thickness-to-radius ratio. The latter, together with the greater resorption of the media than adventitia, related with the measured opening angle decrease in propranolol-treated rats. CONCLUSIONS The geometrical/biomechanical remodeling was mediated by the hemodynamic effects of propranolol treatment, namely the reduced blood flow, and served to normalize in vivo hoop stresses as well as vessel compliance.

中文翻译：

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在动物模型中长期服用普萘洛尔引起的大动脉生物力学，几何和结构重塑。

背景技术尽管β-肾上腺素能阻断剂在临床上可用于治疗许多形式的心血管疾病，但是已经对β-肾上腺能阻断剂在大动脉功能/结构上的作用给予了有限的关注。目的评估β受体阻滞剂对两个主要弹性动脉的生物力学特性，几何形状和组织学结构的长期影响。方法健康的雄性大鼠随食物一起喝水，而在饮用水中添加普萘洛尔可产生β受体阻滞作用。三个月后切除胸主动脉和颈动脉，进行生物力学测试（破坏和膨胀-扩张），并进行几何和组织学评估。结果：经普萘洛尔治疗的大鼠胸主动脉比未治疗的大鼠纵向增强力量，归因于外膜胶原蛋白含量的增加。在低生理压力下，经心得安治疗的大鼠中颈动脉可扩张性增加，这是由于内侧胶原蛋白含量降低所致。结构重塑的特征在于管腔直径，壁质量和厚度半径比的减小。后者，与外膜相比，介质的吸收更大，与经心得安治疗的大鼠中测得的张开角减小有关。结论普萘洛尔治疗的血液动力学效应（即血流减少）介导了几何/生物力学重塑，并可以正常化体内环向压力和血管顺应性。是由于内侧胶原蛋白含量降低所致。结构重塑的特征在于管腔直径，壁质量和厚度半径比的减小。后者，与外膜相比，介质的吸收更大，与经心得安治疗的大鼠中测得的张开角减小有关。结论普萘洛尔治疗的血液动力学效应（即血流减少）介导了几何/生物力学重塑，并可以正常化体内环向压力和血管顺应性。是由于内侧胶原蛋白含量降低所致。结构重塑的特征在于管腔直径，壁质量和厚度半径比的减小。后者，与外膜相比，介质的吸收更大，与经心得安治疗的大鼠中测得的张开角减小有关。结论普萘洛尔治疗的血液动力学效应（即血流减少）介导了几何/生物力学重塑，并可以正常化体内环向压力和血管顺应性。