Palmer Olivia R, Chiu Calvin B, Cao Amos, Scheven Ulrich M, Diaz Jose A, Greve Joan M
Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.
Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.
Ann Anat. 2017 Nov;214:43-52. doi: 10.1016/j.aanat.2017.08.004. Epub 2017 Sep 1.
Although widely used as a preclinical model for studying venous diseases, there is a scarcity of in vivo characterizations of the naïve murine venous system. Additionally, previous studies on naïve veins (ex vivo) have not included the influence of surrounding structures and biomechanical forces. Using MRI, we noninvasively quantified the cross-sectional area, cyclic strain, and circularity of the venous system in young and old, male and female C57BL/6 mice. We investigated the most common venous locations used to perform venous disease research: the common jugular vein, suprarenal inferior vena cava (IVC), infrarenal IVC, common iliac vein, and common femoral vein. Our results elucidate age-dependent changes in venous cross-sectional area, which varied by location. Maximum cyclic strain, a parameter of lumen expansion, showed 10% change across the cardiac cycle, approximately half the magnitude of arteries. Veins demonstrated noncircular shapes, particularly in the core vasculature. The cardiovascular stressor dobutamine had only a small impact on the venous system. Also, our data demonstrate that the peripheral veins tend to decrease in cross-sectional area and circularity with age. Conversely, the IVC tends to increase in size and circularity with age, with males exhibiting larger variability in response to dobutamine compared to females. This work provides a foundation for drawing age and sex comparisons in disease models, and represents the first in vivo characterization of the murine venous system at rest and during the application of a pharmacological exercise surrogate.
尽管作为研究静脉疾病的临床前模型被广泛使用，但对未经处理的小鼠静脉系统的体内特征描述却很匮乏。此外，以往对未经处理静脉（体外）的研究并未考虑周围结构和生物力学力的影响。我们利用磁共振成像（MRI）对年轻和年老的雄性及雌性C57BL/6小鼠静脉系统的横截面积、周期性应变和圆度进行了无创量化。我们研究了用于进行静脉疾病研究的最常见静脉位置：颈静脉、肾上腺下腔静脉（IVC）、肾下IVC、髂总静脉和股总静脉。我们的结果阐明了静脉横截面积随年龄的变化，且因位置而异。最大周期性应变是管腔扩张的一个参数，在心动周期中显示出10%的变化，约为动脉变化幅度的一半。静脉呈现出非圆形形状，尤其是在核心血管系统中。心血管应激源多巴酚丁胺对静脉系统的影响很小。此外，我们的数据表明，外周静脉的横截面积和圆度往往会随着年龄的增长而减小。相反，IVC的大小和圆度往往会随着年龄的增长而增加，与雌性相比，雄性对多巴酚丁胺的反应表现出更大的变异性。这项工作为在疾病模型中进行年龄和性别比较奠定了基础，并且代表了对静息状态下以及应用药理学运动替代物期间的小鼠静脉系统的首次体内特征描述。
