2010 | OriginalPaper | Chapter
Differential Effects of Shear Forces and Pressure on Blood Vessel Metabolism and Function in a Perfusion Model
Authors : M. Hoenicka, L. Wiedemann, S. Schrammel, C. Schmid, D. E. Birnbaum
Published in: 6th World Congress of Biomechanics (WCB 2010). August 1-6, 2010 Singapore
Publisher: Springer Berlin Heidelberg
Activate our intelligent search to find suitable subject content or patents.
Select sections of text to find matching patents with Artificial Intelligence. powered by
Select sections of text to find additional relevant content using AI-assisted search. powered by
Tissue engineering protocols commonly incorporate mechanical stimuli like pulsatile flow and luminal pressure to adapt the constructs to the biomechanical requirements of the target circulation. This study investigated the effects of shear forces and of luminal pressure on blood vessel metabolism and function using bovine veins as a model. Veins were perfused for four days in M199 at 40 ml/min. Shear forces were increased by adjusting the viscosity of the medium to that of blood. Some veins were additionally treated with luminal pressure. Control groups were either denuded or perfused with 60 ml/min to assess the influences of endothelium and of elevated flow rates, respectively. Physiological shear forces were sufficient to maintain endothelial integrity, unless superphysiological flow rates were applied. Reductive capacities were not affected by any of the perfusion conditions. Responses to the receptor-dependent vasoconstrictor noradrenalin were increased after perfusing with physiological shear forces and luminal pressure. This also induced a shift of the metabolism from glycolysis and lactate fermentation to the use of alternative substrates other than glucose. Mechanically denuded control vessels were prone to apoptosis and showed an altered metabolism as well. However, denuded vessels treated with luminal pressure also showed improved responses to vasoconstrictors compared to denuded controls. These results indicate that mechanical challenges are required to maintain endothelial integrity and to improve contractile function of vessels in perfusion systems. Metabolic patterns change with mechanical challenges, and care should be taken to provide sufficient amounts of substrates other than glucose for energy metabolism.