Jaldin Rodrigo Gibin, Castardelli Édson, Perobelli Juliana Elaine, Yoshida Winston Bonetti, de Castro Rodrigues Antônio, Sequeira Júlio Lopes, Paiva Sérgio Alberto Rupp
Department of Surgery and Orthopaedics, São Paulo State University Medical School, Botucatu, Brazil.
Ann Vasc Surg. 2013 Aug;27(6):791-800. doi: 10.1016/j.avsg.2013.03.002.
Smoking is the most relevant environmental factor that affects the development of aortic aneurysm. Smokers have elevated levels of elastase activity in the arterial wall, which leads to weakening of the aorta. The aim of this study was to verify whether cigarette smoke exposure itself is capable of altering the aortic wall.
Forty-eight Wistar rats were divided into 2-, 4-, and 6-month experimental periods and into 2 groups: smokers (submitted to smoke exposure at a rate of 40 cigarettes/day) and nonsmokers. At the end of the experimental periods, the aortas were removed and cross-sectioned to obtain histologic specimens for light microscopic and morphometric analyses. The remaining longitudinal segments were stretched to rupture and mechanical parameters were determined.
A degenerative process (i.e., a reduction in elastic fibers, the loss of lamellar arrangement, and a reduction of smooth muscle cells) was observed, and this effect was proportional in intensity to the period of tobacco exposure. We observed a progressive reduction in the yield point of the thoracic aorta over time (P < 0.05). There was a decrease in stiffness (P < 0.05) and in failure load (P < 0.05) at 6 months in the abdominal aorta of rats in the smoking group.
Chronic exposure to tobacco smoke can affect the mechanical properties of the aorta and can also provoke substantial structural changes of the arterial wall.
吸烟是影响主动脉瘤发展的最相关环境因素。吸烟者动脉壁中的弹性蛋白酶活性水平升高，这会导致主动脉变弱。本研究的目的是验证香烟烟雾暴露本身是否能够改变主动脉壁。
将48只Wistar大鼠分为2个月、4个月和6个月的实验期，并分为2组：吸烟者（以每天40支香烟的速率接受烟雾暴露）和非吸烟者。在实验期结束时，取出主动脉并进行横截面切片，以获得用于光学显微镜和形态计量分析的组织学标本。将剩余的纵向节段拉伸至破裂，并测定力学参数。
观察到一种退行性过程（即弹性纤维减少、层状排列丧失和平滑肌细胞减少），并且这种效应的强度与烟草暴露时间成正比。我们观察到胸主动脉的屈服点随时间逐渐降低（P < 0.05）。吸烟组大鼠腹主动脉在6个月时刚度（P < 0.05）和破坏载荷（P < 0.05）降低。
长期暴露于烟草烟雾可影响主动脉的力学性能，还可引发动脉壁的实质性结构变化。
