Blood Vessel Sprouting (image) University of Pennsylvania Caption With lifesaving applications possible in both inhibiting and accelerating the creation of new blood vessels, a more fundamental understanding of what regulates angiogenesis is needed. Now, researchers at the University of Pennsylvania, Boston University and Harvard University have uncovered the existence of a threshold above which fluid flowing through blood vessel walls causes new capillaries to sprout. Credit Boston University Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.