Effect of hyperosmolarity and hypoosmolarity on vascular remodeling : either way is a wrong way
Résumé
The formation of the vascular architecture is a very active and important area of research. A lot of thrust has been put on the study of the effect of haemodynamics and especially the role of shear stress 1-5 on vascular pattern formation. However, the architecture of blood vessels is also quite sensitive to transmural pressure 6-7. Transmural pressure itself is dependent on metabolism. The effect of transmural pressure has received less attention. In many pathologies tissue pressure plays a crucial role in vascular patterning. At short time scales tensile or compressive stresses may facilitate or hinder perfusion, and at longer time scales stresses impact vascular remodeling. Here, we report a study of the effect of osmotic shocks on the dynamics of vascular pattern formation. Working with the chicken Chorio Allantoic Membrane 8 and Yolk Sac 9 , we evidence that blood vessels are in a state of dynamic homeostasis, and that osmotic shocks, either hypertonic or hypotonic, lead to vascular collapse, by entirely different mechanisms. Hypoosmolarity leads to dilation of the interstitium by water uptake, and hyperosmolarity leads to solvent outflux, tension driven shrinkage and subsequent vascular collapse. In summary, compressive and tensile forces in the tissue are finely balanced to enable a proper vascular patterning, shifting the mechanical state either way, is a wrong way.
Domaines
Sciences du Vivant [q-bio]Origine | Fichiers produits par l'(les) auteur(s) |
---|