The 27th Annual Meeting of the Japanese Society of Biorheology

摘要

Leukocytes and platelets flowing in the blood stream use specific receptor/ligand interactions to tether to the vessel wall and slow down, so that local activation and engagement of integrins for firm adhesion is possible. For leukocytes the tethering molecules are called selectins and on platelets they are called GP1b. This lecture describes the effects of flow induced force on the bond lifetimes of these receptor/ligand pairs. Emphasis is placed on the GP1b-von Willebrand Factor interaction - crucial for understanding arterial thrombosis. The effects of mutations in GP1b on these tethering interactions and possible molecular structural implications are discussed. Comparisons are made with the detailed bond biomechanics found in the selectin interactions. An interesting phenomenon is described where in some ranges of flow, increasing force decreases bond liketime (slip bonds), but in other ranges increasing force increases bond lifetime (catch bonds).