Allt G, Lawrenson J G
Reta Lila Weston Institute of Neurological Studies, University College London Medical School, London, UK.
Cells Tissues Organs. 2001;169(1):1-11. doi: 10.1159/000047855.
Pericytes are perivascular cells with multifunctional activities which are now being elucidated. The functional interaction of pericytes with endothelial cells (EC) is now being established, using current molecular and cytochemical techniques. The detailed morphology of the pericyte has been well described. Pericytes extend long cytoplasmic processes over the surface of the EC, the two cells making interdigitating contacts. At points of contact, communicating gap junctions, tight junctions and adhesion plaques are present. Pericytes appear to show both structural and functional heterogeneity. The coverage of EC by pericytes varies considerably between different microvessel types and the location of pericytes on the microvessel is not random but appears to be functionally determined. Interaction between pericytes and EC is important for the maturation, remodelling and maintenance of the vascular system via the secretion of growth factors or modulation of the extracellular matrix. There is also evidence that pericytes are involved in the transport across the blood-brain barrier and the regulation of vascular permeability. The long-standing view that pericytes are the microvessel equivalent of larger vessel smooth muscle cells and are contractile is being reassessed using current methods. An important role for pericytes in pathology, and neuropathology in particular, has been indicated in hypertension, diabetic retinopathy, Alzheimer's disease, multiple sclerosis and CNS tumour formation.
周细胞是具有多种功能活性的血管周围细胞，目前其功能正在被阐明。利用当前的分子和细胞化学技术，周细胞与内皮细胞（EC）之间的功能相互作用正在被确立。周细胞的详细形态已得到充分描述。周细胞在EC表面伸出长长的细胞质突起，这两种细胞形成相互交错的接触。在接触点处，存在通讯性缝隙连接、紧密连接和黏附斑。周细胞似乎表现出结构和功能的异质性。不同微血管类型之间周细胞对EC的覆盖程度差异很大，并且周细胞在微血管上的位置并非随机，而是似乎由功能决定。周细胞与EC之间的相互作用对于血管系统通过生长因子的分泌或细胞外基质的调节实现成熟、重塑和维持很重要。也有证据表明周细胞参与了血脑屏障的转运和血管通透性的调节。长期以来认为周细胞相当于较大血管平滑肌细胞且具有收缩性的观点，正在用当前方法重新评估。周细胞在病理学尤其是神经病理学中的重要作用，已在高血压、糖尿病视网膜病变、阿尔茨海默病、多发性硬化症和中枢神经系统肿瘤形成中得到证实。
