The extracellular matrix is an integral component of the vasculature, contributing to both developmental processes and structural and functional homeostasis. We describe here the types of extracellular matrices that occur in different blood vessel types, ranging from capillaries to veins, venules and arteries, and focus on the endothelial basement membranes and the laminin family of proteins. We summarize data on the molecular composition of endothelial basement membranes, the structure and in vivo expression patterns of the main endothelial laminin isoforms (laminins 411 and 511) and their, to date, deciphered functions in the vasculature. A significant portion of the review focuses on postcapillary venules and leukocyte extravasation and how the endothelial laminins affect adhesion and migration of different leukocyte types, but also how laminins affect endothelial barrier function by modulating expression and localization of endothelial cell-cell junction molecules, and how these effects differ in CNS versus non-CNS tissues. Comparisons are made to small artery dilation in response to shear flow, which has been shown to be dependent on endothelial laminins and junctional complexes. The data discussed support a central role for basement membrane laminins in different aspects of micro- and macro-vessel endothelial function, but also reveal that many open questions remain, including the contribution of perivascular cells which are either embedded or in direct contact with the endothelial cell basement membrane laminins.

细胞外基质是脉管系统不可或缺的组成部分，有助于发育过程以及结构和功能稳态。我们在这里描述发生在不同血管类型中的细胞外基质的类型，范围从毛细血管到静脉，小静脉和动脉，并着重于内皮基底膜和层粘连蛋白家族。我们总结了内皮基底膜的分子组成，结构和体内数据主要内皮层粘连蛋白同工型（层粘连蛋白411和511）的表达模式及其迄今为止在脉管系统中破译的功能。审查的主要内容集中在毛细血管后小静脉和白细胞的渗出以及内皮层粘连蛋白如何影响不同白细胞类型的粘附和迁移，以及层粘连蛋白如何通过调节内皮细胞-细胞连接分子的表达和定位如何影响内皮屏障功能，以及这些影响在CNS与非CNS组织。对响应剪切流的小动脉扩张进行了比较，已显示这取决于内皮层粘连蛋白和连接复合物。讨论的数据支持了基底膜层粘连蛋白在微血管和大血管内皮功能不同方面的核心作用，但也揭示了许多悬而未决的问题，包括嵌入或与内皮直接接触的血管周细胞的作用细胞基底膜层粘连蛋白。