Department of Biomedicine, University of Bergen, Norway.
Acta Physiol (Oxf). 2009 Dec;197(4):305-11. doi: 10.1111/j.1748-1716.2009.02025.x. Epub 2009 Jul 23.
The vascular protein permeability is dependent on the integrity of the vascular wall. The heart capillaries in male mice lacking beta3 integrins have an immature phenotype. Previously, we have demonstrated a role for alphavbeta3 integrins in control of interstitial fluid pressure (Pif) and thereby in the fluid flux during inflammation. We wanted to explore a possible role for alphavbeta3 integrins in controlling capillary protein permeability during control situation and inflammation.
We performed double-tracer and microdialysis experiments on beta3-integrin-deficient mice and wild type control mice. We also measured blood pressure and heart rate in the two mice strains.
We found reduced albumin extravasation (during 25 min) in the heart capillaries (0.053 +/- 0.003 vs. 0.087 +/- 0.009 mL g(-1) dw, P < 0.05), and an increased cardiac mass/body weight (5.3 x 10(-3) +/- 0.3 x 10(-3) vs. 3.8 x 10(-3) +/- 0.1 x 10(-3), P < 0.01) in the beta3-integrin-deficient mice (n = 6) compared with the controls (n = 6). Heart rate and blood pressure were the same in mice with and without beta3-integrins. No difference in permeability was found in other tissues studied, or under local inflammation.
These results show a function for the alphavbeta3 integrin in the regulation of protein permeability, selective for the heart capillaries.
血管蛋白通透性依赖于血管壁的完整性。缺乏β3 整合素的雄性小鼠心脏毛细血管具有未成熟的表型。先前，我们已经证明αvβ3 整合素在控制间质液压力（Pif）以及炎症期间的流体通量方面起作用。我们想探讨αvβ3 整合素在控制正常情况下和炎症时毛细血管蛋白通透性中的可能作用。
我们对β3 整合素缺陷小鼠和野生型对照小鼠进行了双示踪剂和微透析实验。我们还测量了两种小鼠品系的血压和心率。
我们发现心脏毛细血管中的白蛋白外渗减少（25 分钟期间）（0.053 ± 0.003 对 0.087 ± 0.009 mL g(-1) dw，P < 0.05），β3 整合素缺陷小鼠（n = 6）的心脏质量/体重比增加（5.3 x 10(-3) ± 0.3 x 10(-3) 对 3.8 x 10(-3) ± 0.1 x 10(-3)，P < 0.01），而对照组（n = 6）则没有。β3 整合素存在与否的小鼠心率和血压相同。在其他研究的组织中或局部炎症下没有发现通透性的差异。
这些结果表明αvβ3 整合素在调节蛋白通透性方面具有选择性，选择性针对心脏毛细血管。
