Bradykinin does not induce gap formation between human endothelial cells
- 2 October 2007
- journal article
- cell and-molecular-physiology
- Published by Springer Science and Business Media LLC in Pflügers Archiv - European Journal of Physiology
- Vol. 455 (6), 1007-1016
- https://doi.org/10.1007/s00424-007-0352-x
Abstract
Generally, a formation of paracellular gaps is considered to be the main pathway for fluid passage across endothelia. A model substance for studies in vitro is the vasodilatory peptide bradykinin, which has important functions in inflammation and vascular fluid balance. The mechanisms by which it increases endothelial permeability are not as yet clearly defined. Paracellular gap formation was approached using atomic force microscopy (AFM) on human umbilical vein endothelial cells grown on permeable filter supports. To further distinguish between para- vs transcellular fluid passage, a standard permeability assay was modified by a rapid cooling protocol to specifically inhibit vesicular transport pathways. Cell layers stimulated with bradykinin (1 μM) did not show significant alterations at the cellular junctions. However, gap formation was easily detectable by AFM after addition of the Ca2+-ionophore ionomycin (1 μM), which was taken as a positive control for cellular contraction. At 37°C, bradykinin enhanced fluorescein isothiocyanate-dextran permeability by 48 ± 11%. This was blocked by rapid cooling of the sample, indicating a vesicular mechanism of fluid transport. Contrastingly, ionomycin-induced permeability (259 ± 43%) persisted after cooling (230 ± 44%), thereby confirming paracellular gap formation. Accordingly, endocytotic vesicle formation, as detected by fluorescence microscopy, was upregulated by 68 ± 15% through bradykinin action, while ionomycin did not show a significant effect (7 ± 26%). The combined results of both permeability and morphometric studies lead to the conclusion that bradykinin promotes transcellular fluid passage rather than increasing paracellular diffusion.Keywords
This publication has 43 references indexed in Scilit:
- Cardiovascular and renal function of angiotensin II type-2 receptorsCardiovascular Research, 2004
- Transcellular transport as a mechanism of blood-brain barrier disruption during strokeFrontiers in Bioscience-Landmark, 2004
- Wortmannin alters the intracellular trafficking of the bradykinin B2 receptor: role of phosphoinositide 3-kinase and Rab5Biochemical Journal, 2003
- Role of the bradykinin B2 receptor for the local and systemic inflammatory response that follows severe reperfusion injuryBritish Journal of Pharmacology, 2003
- Inhibition of contractile activation reduces reoxygenation-induced endothelial gap formationCardiovascular Research, 2003
- Transendothelial Transport: The Vesicle ControversyJournal of Vascular Research, 2002
- Endothelial protease-activated receptor-2 induces tissue factor expression and von Willebrand factor releaseBritish Journal of Haematology, 1999
- Endothelial Gaps as Sites for Plasma Leakage in InflammationMicrocirculation, 1999
- Myosin light chain kinase-regulated endothelial cell contraction: the relationship between isometric tension, actin polymerization, and myosin phosphorylation.The Journal of cell biology, 1995
- Changes in surface topography in endothelial monolayers with time at confluence: influence on subcellular shear stress distribution due to flowBiochemistry and Cell Biology, 1995