A DEVICE FOR THE APPLICATION OF CYCLIC TWIST AND EXTENSION ON PERFUSED VASCULAR SEGMENTS

Cyclic strain is known to influence many aspects of vascular cell biol ogy, including macromolecular biosynthesis, cell proliferation, and ce ll morphology. The simulation of the cyclic strain associated with the vasculature in situ has been carried out mostly using devices that ma nipulated flat membranes on which the cells of choice are cultured. Th e purpose of this work was to create an apparatus wherein cyclic strai ns consistent with those found in native blood vessels could be applie d to intact three-dimensional (tubular) specimens perfused ex vivo. Th e cyclic strain protocols using our apparatus may be any combination o f axial stretch and twist. Concurrently, the perfusion flow and shear stress are controlled as desired. Vessel diameter, intraluminal pressu re, volume flow, and regional strain are measured and stored on line. To illustrate the application of the device, we present hemodynamic an d kinematic data collected from a human saphenous vein segment perfuse d under steady-flow conditions while subjected to cyclic stretch and t wist.