Spatial distribution and mechanical function of elastin in resistance arteries: a role in bearing longitudinal stress.
Spatial distribution and mechanical function of elastin in resistance arteries: a role in bearing longitudinal stress.
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DOI：
10.1161/atvbaha.111.236570
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发表时间：
2011-12
期刊：
影响因子：
--
通讯作者：
Hill MA
中科院分区：
文献类型：
--
作者：
Clifford PS;Ella SR;Stupica AJ;Nourian Z;Li M;Martinez-Lemus LA;Dora KA;Yang Y;Davis MJ;Pohl U;Meininger GA;Hill MA
尽管细胞外基质（ECM）在血管信号传导中发挥作用，但对特定ECM蛋白与血管平滑肌细胞（VSMCs）之间的复杂结构排列知之甚少。我们的目的是检查假设外膜弹性蛋白纤维占主导地位的血管受到纵向拉伸。分离提睾肌（CM）小动脉，使其产生自发张力，并与脑小动脉进行比较。使用3D共聚焦显微镜观察血管壁内的ECM。将加压的小动脉固定并用以下物质染色：Alexa 633酰肼（作为非选择性ECM标记物）、抗弹性蛋白或抗1型胶原抗体和荧光核染色。将CM小动脉暴露于弹性蛋白酶5分钟引起血管段的不可逆延长，这在脑动脉中未观察到。使用3D成像在CM小动脉上显示纵向弹性蛋白纤维，但证实在脑血管中不存在。纤维也不同于I型胶原纤维，并通过弹性蛋白酶处理降解。这些结果表明，弹性蛋白的重要性，在轴承纵向应力的小动脉壁，这些纤维限制VSMCs。骨骼肌和大脑小动脉之间的差异可能反映了局部机械环境的差异，例如暴露于纵向拉伸。
Despite the role that extracellular matrix (ECM) plays in vascular signaling, little is known of the complex structural arrangement between specific ECM proteins and vascular smooth muscle cells (VSMCs). Our objective was to examine the hypothesis that adventitial elastin fibers are dominant in vessels subject to longitudinal stretch. Cremaster muscle (CM) arterioles were isolated and allowed to develop spontaneous tone and compared with small cerebral arteries. 3D confocal microscopy was used to visualize ECM within the vessel wall. Pressurized arterioles were fixed and stained with: Alexa 633 Hydrazide (as a non-selective ECM marker), anti-elastin or anti-type 1 collagen antibody and a fluorescent nuclear stainExposure of CM arterioles to elastase for 5 min caused an irreversible lengthening of the vessel segment not observed in cerebral arteries. Longitudinal elastin fibers were demonstrated on CM arterioles using 3D imaging but were confirmed to be absent in cerebral vessels. The fibers were also distinct from type I collagen fibers and were degraded by elastase treatment. These results indicate the importance of elastin in bearing longitudinal stress in the arteriolar wall and that these fibers constrain VSMCs. Differences between skeletal muscle and cerebral small arteries may reflect differences in the local mechanical environment such as exposure to longitudinal stretch.