Dodge A B, Hechtman H B, Shepro D
Department of Biology, Boston University, Massachusetts 02215.
Cell Motil Cytoskeleton. 1991;18(3):180-8. doi: 10.1002/cm.970180304.
A silicone rubber assay is used in conjunction with morphometric measurements to characterize in vitro the contractile properties of retinal pericytes in response to endothelial secreted factors. Factor(s) present in conditioned media derived from pulmonary and retinal microvascular endothelial cells and pulmonary artery endothelial cells promote pericyte contractions. Using a radioimmunoassay significant levels of endothelin immunoreactivity are measured in conditioned media obtained from all three cell lines. Thrombin treatment enhanced endothelin-like secretions by pulmonary microvascular endothelial cells, but significantly reduced levels of endothelin-like immunoreactivity secreted by retinal microvascular endothelial cells. Synthetic endothelin and thromboxane A2 (TxA2) stimulate pericyte contractions, whereas prostaglandin I2 (PGI2) promotes pericyte relaxation. Thrombin and angiotension II (ang II) have no effect on pericyte contractility. However, using cocultures of pericytes and endothelial cells we observe endothelial-dependent pericyte contractions in response to thrombin and ang II. Thrombin and ang II stimulate the release of endothelial-derived contracting factors, with characteristics similar to endothelin. These data suggest microvascular endothelial cell-pericyte interactions may regulate, at least in part, microvessel contractility.
硅橡胶试验与形态测量相结合，用于在体外表征视网膜周细胞对内皮细胞分泌因子的收缩特性。来自肺和视网膜微血管内皮细胞以及肺动脉内皮细胞的条件培养基中存在的因子可促进周细胞收缩。使用放射免疫分析法，在从所有三种细胞系获得的条件培养基中检测到显著水平的内皮素免疫反应性。凝血酶处理增强了肺微血管内皮细胞的内皮素样分泌，但显著降低了视网膜微血管内皮细胞分泌的内皮素样免疫反应性水平。合成内皮素和血栓素A2（TxA2）刺激周细胞收缩，而前列腺素I2（PGI2）促进周细胞松弛。凝血酶和血管紧张素II（ang II）对周细胞收缩性没有影响。然而，使用周细胞和内皮细胞的共培养物，我们观察到周细胞对凝血酶和ang II的内皮依赖性收缩。凝血酶和ang II刺激内皮衍生的收缩因子的释放，其特征类似于内皮素。这些数据表明微血管内皮细胞-周细胞相互作用可能至少部分调节微血管收缩性。
