Collagen XII has a short collagenous tail and a very large, three-armed NC3 domains consisting primarily of fibronectin type III repeats. Differential splicing within this domain gives rise to a large (320 kD) and a small (220 kD) subunit; the large but not the small can carry glycosaminoglycan. To investigate whether collagen XII variants have distinct expression patterns and functions, we gen...

Factor XII ia a single-chain beta-globulin serine protease with a molecular weight of 80,000 84,000 daltons and a plasma concentration of approximately 30 pg/mL. Proteolytic cleavage of factor XII is mediated by charged surfaces (glass, kaolin, cellite, dextran sulfate, endotoxin, urates, crude collagen, sulfatides), autoactivation, and kallikrein. Prekallikrein, factor XI, factor VII, plasmino...

Hypoglossal (XII) nerve recordings indicate that pulmonary C-fiber (PCF) receptor activation reduces inspiratory bursting and triggers tonic discharge. We tested three hypotheses related to this observation: 1) PCF receptor activation inhibits inspiratory activity in XII branches innervating both tongue protrudor muscles (medial branch; XIImed) and retractor muscles (lateral branch; XIIlat); 2)...

Thrombin can activate factor XI in the presence of dextran sulfate or sulfatides. However, a physiological cofactor for thrombin activation of factor XI has not been identified. We examined this question in a cell-based, tissue factor-initiated model system. In the absence of factor XII, factor XI enhanced thrombin generation in this model. The effect on thrombin generation was reproduced by 2 ...

The release of histones from dying cells is associated with microvascular thrombosis and, because histones activate platelets, this could represent a possible pathogenic mechanism. In the present study, we assessed the influence of histones on the procoagulant potential of human platelets in platelet-rich plasma (PRP) and in purified systems. Histones dose-dependently enhanced thrombin generati...